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That's More Like It: Multiple Exemplars Facilitate Word Learning
Infant and Child Development
Abstract
Previous research indicates learning words facilitates categorisation. The current study explores how categorisation affects word learning. In the current study, we investigated whether learning about a category facilitates retention of newly learned words by presenting 2-year-old children with multiple referent selection trials to the same object category. In Experiment 1, children either encountered the same exemplar repeatedly or encountered multiple exemplars across trials. All children did very well on the initial task; however, only children who encountered multiple exemplars retained these mappings after a short delay. Experiment 2 replicated and extended this finding by exploring the effect of within-category variability on children's word retention. Children encountered either narrow or broad exemplars across trials. Again, all children did very well on the initial task; however, only children who encountered narrow exemplars retained mappings after a short delay. Overall, these data offer strong evidence that providing children with the opportunity to compare across exemplars during fast mapping facilitates retention.
... In order to truly learn a word from a picture, children must also retain and appropriately extend labels to symbolised referents in the absence of the picture for comparison. Previous studies of word learning from objects have shown that associating a novel label with multiple exemplars of a referent can facilitate both retention (Twomey, Ranson, & Horst, 2014) and generalisation (Perry, Samuelson, Malloy, & Schiffer, 2010) by highlighting crucial category-relevant details (e.g., shape) and diverting attention away from category-irrelevant details (e.g., colour). Here, for the first time, we investigate whether two-and three-year-olds' ability to extend labels from memory representations of pictures is facilitated by exposure to multiple exemplars during teaching. ...
... Children's retention and generalisation of word-picture-object relationships was then assessed after a 5-minute delay by asking children to identify 3-D object referents for each novel label. Based on previous evidence regarding object name learning (e.g., Perry et al., 2010;Twomey et al., 2014), we predicted that children would retain and generalise labels with significantly greater accuracy in the multiple exemplars condition. We also tentatively predicted that three-year-olds may extend labels to symbolised referents with significantly greater accuracy than two-year-olds due to their increased experience of learning from pictures (Callaghan et al., 2011) and more developed memory mechanisms subserving general word learning (Cheung et al., 2022). ...
... Based on the most relevant data that informed this research, our sample sizes were determined by power simulations performed using 'Power ANalysis for GEneral Anova' (PANGEA, Version 0.2; Westfall, 2015). We aimed to detect a key finding reported in Twomey et al. (2014): that neurotypical two-year-olds retain novel words with significantly greater accuracy when taught via multiple exemplars than single exemplars. Twomey et al. utilised a between-subjects design in which 12 children were assigned to the single exemplar condition and 12 were assigned to the multiple exemplars condition. ...
We investigated whether preschool children’s extension of labels from memory representations of pictures is enhanced by exposure to multiple exemplars during teaching. Neurotypical 2-year-olds (N = 23) and 3-year-olds (N = 19) mapped novel word-picture associations in a referent selection task. Their retention and generalisation of labels was then assessed after 5 min with depicted 3-D objects. During referent selection, children were presented with a single variant of each novel picture (single exemplar condition) or two differently coloured variants of each novel picture (multiple exemplars condition). Both age groups extended labels to similarly coloured objects with significantly greater accuracy when taught with multiple exemplars. Three-year-olds also generalised labels to differently coloured category members with significantly greater accuracy in the multiple exemplars condition, where they outperformed two-year-olds. We propose that comparing multiple pictures of to-be-learned referents strengthens encoding of category-defining shape, facilitating extension of labels to objects from memory.
... A large body of work demonstrates the benefits of comparing multiple objects (i.e., considering two or more instances simultaneously) versus labeling a single object for category learning and generalization (Gentner & Namy, 1999;Graham, Namy, Gentner, & Meagher, 2010;Medin, Goldstone, & Gentner, 1993;Namy & Clepper, 2010;Namy & Gentner, 2002;Namy, Smith, & Gershkoff-Stowe, 1997;Spalding & Ross, 2000;Twomey, Ranson, & Horst, 2014;Vukatana, Graham, Curtin, & Zepeda, 2015). For example, providing learners with opportunities to compare multiple instances has been shown to result in higher levels of exhaustive classification (Namy et al., 1997), increased ability to disregard irrelevant perceptual similarity in favor of relational matches (Gentner, Anggoro, & Klibanoff, 2011), accelerated verb learning (Childers, Paik, Flores, & Lai, 2017), facilitated solving of complex relational problems (Dixon & Bangert, 2004), and increased likelihood or reasoning through analogy (Gick & Holyoak, 1983). ...
... Multiple examples may also be more beneficial when learners must retain word-object pairings over a delay (Twomey et al., 2014). Recent research suggests that despite the fact that children can readily link a word to its referent in fast mapping studies, they appear to have difficulty in retaining that link over short time delays. ...
... However, when children were asked to select the referent after a 5-min delay, they responded at chance levels, suggesting that children failed to retain the object-label link over the short delay. Similar work that included multiple exemplars of a category found that children were able to generalize over a delay when given multiple examples but not when given a single example (Twomey et al., 2014). In addition, an eye-tracking study (Bion, Borovsky, & Fernald, 2013) found that children had difficulty in retaining a label after a delay when training involved a single example. ...
A large body of research indicates that children can map words to categories and generalize the label to new instances of the category after hearing a single instance of the category labeled. Additional research demonstrates that word learning is enhanced when children are presented with multiple instances of a category through comparison or contrast. In this study, 3-year-old children participated in a novel noun generalization task in which a label was given for either (a) a single instance of a category, (b) multiple instances of a category, or (c) contrasting a category instance with non-category members. Children were asked to extend the label to a new category at test either immediately (Study 1) or after a 10-s delay (Study 2). The results indicate that when tested immediately, children who heard a single instance labeled outperformed children who were presented with multiple instances. However, when tested after a brief delay, there was no difference among the conditions.
... In a series of 3D object word learning tasks, Twomey, Ranson, and Horst (2014) trained 30-monthold toddlers with novel word-object mappings and demonstrated that children retained words only after encountering multiple perceptually similar exemplars of each novel object category. We reasoned that 10-month-old infants may likewise benefit from exposure to multiple category exemplars. ...
... Thus, infants' failure to learn word-category associations in Experiment 2 is unlikely to stem from an inability to categorize. Rather, the lack of retention of these associations may be due to the increased cognitive load of encoding a category plus a label in Experiment 2 versus an individual object and a label in Experiment 1. Notably, this pattern of findingsretention after the same exemplar repeatedly but failure to retain after multiple exemplarsis the opposite of Twomey et al. (2014) findings for toddlers. We return to this issue in the General Discussion. ...
... When provided with richer perceptual input via multiple exemplars during training in Experiment 2, infants failed to learn labels. This finding diverges from the effect of variability on toddlers' word learning (Twomey et al., 2014), and from tasks which have shown the benefit of multiple exemplars in other domains (e.g., Kovack-Lesh & Oakes. 2007;Quinn & Bhatt, 2010;Rost & McMurray, 2009). ...
In this series of experiments, we tested the limits of young infants’ word learning and generalization abilities in light of recent findings reporting sophisticated word learning abilities in the first year of life. Ten-month-old infants were trained with two word-object pairs and tested with either the same or different members of the corresponding categories. In Experiment 1, infants showed successful learning of the word-object associations, when trained and tested with a single exemplar from each category. In Experiment 2, infants were presented with multiple within-category items during training but failed to learn the word-object associations. In Experiment 3, infants were presented with a single exemplar from each category during training, and failed to generalize words to a new category exemplar. However, when infants were trained with items from perceptually and conceptually distinct categories in Experiment 4, they showed weak evidence for generalization of words to novel members of the corresponding categories. It is suggested that word learning in the first year begins as the formation of simple associations between words and objects that become enriched as experience with objects, words and categories accumulates across development.
... Twomey et al. [29] suggest, however, that there are limits to the effects of variability on learning: although 30-month-olds learned labels for categories when the objects varied in colour (but not when they were in identical colours), children did not learn category labels when objects varied in shape and colour. Thus, too much variability disrupted children's learning of category labels. ...
... They found that children only showed target recognition in the variable condition which led them to assume that decontextualization helped the children to form strong word representations. Nonetheless, they also suggest that increased variability might disrupt successful learning and that this might relate to the learning environment: reduced variability might help in rich learning environments and increased background variability may boost learning in simpler learning environments (see [29,32]). Thus, the effect of variability may vary across contexts and guide attention allocation in different ways, thereby influencing learning behaviour (see [33]). ...
... We interpret these findings to suggest that redundant information from different domains supports the forming of rich lexical representations, but only if this information highlights the wordobject association and does not distract from it, and only towards the third year of life. This is in line with the literature suggesting a beneficial effect of consistency on word learning [21], in contrast to a beneficial effect of variability on generalization over different members of a category [29,47,48]. Nevertheless, some recent work suggests an impact of lower-level variability (variability in the colour of the background on which objects were presented) on learning of word-object associations [31]. ...
Communication with young children is often multimodal in nature, involving, for example, language and actions. The simultaneous presentation of information from both domains may boost language learning by highlighting the connection between an object and a word, owing to temporal overlap in the presentation of multimodal input. However, the overlap is not merely temporal but can also covary in the extent to which particular actions co-occur with particular words and objects, e.g. carers typically produce a hopping action when talking about rabbits and a snapping action for crocodiles. The frequency with which actions and words co-occurs in the presence of the referents of these words may also impact young children’s word learning. We, therefore, examined the extent to which consistency in the co-occurrence of particular actions and words impacted children’s learning of novel word–object associations. Children (18 months, 30 months and 36–48 months) and adults were presented with two novel objects and heard their novel labels while different actions were performed on these objects, such that the particular actions and word– object pairings always co-occurred (Consistent group) or varied across trials (Inconsistent group). At test, participants saw both objects and heard one of the labels to examine whether participants recognized the target object upon hearing its label. Growth curve models revealed that 18-month-olds did not learn words for objects in either condition, and 30-month-old and 36- to 48-month-old children learned words for objects only in the Consistent condition, in contrast to adults who learned words for objects independent of the actions presented. Thus, consistency in the multimodal input influenced word learning in early childhood but not in adulthood. In terms of a dynamic systems account of word learning, our study shows how multimodal learning settings interact with the child’s perceptual abilities to shape the learning experience.
... Other evidence appears to run counter to this finding. Twomey, Ranson, and Horst (2014) examined the effects of encountering variable exemplars on 2.5-year-old children's gradual, long-term word learning. In their initial experiment, children learned nonword labels when the same object exemplar was presented repeatedly or when multiple object exemplars that differed in color were presented. ...
... However, the 2.5-year-old children only learned in the one context condition and did not benefit from context variability, suggesting a developmental effect for input variability. These results are similar to those of Twomey et al. (2014), who found that too much variability did not aid learning at this young age. Because the objects used in training for the Vlach and Sandhofer (2011) study already varied in color, texture, and perceptual features, perhaps varying the context as well was too much variability for these young children. ...
... The current findings complement prior work by others for typically developing children (Perry et al., 2010;Twomey et al., 2014) and extend them to a clinical population characterized by language deficits. However, it is important to note the differences between studies, particularly that of Perry et al. (2010), which was the most similar to the current study. ...
Purpose
Variability in the input plays an important role in language learning. The current study examined the role of object variability for new word learning by preschoolers with specific language impairment (SLI).
Method
Eighteen 4- and 5-year-old children with SLI were taught 8 new words in 3 short activities over the course of 3 sessions. Half of the children saw 3 identical objects corresponding to each new word during training (No Variability group); the other half of the children saw 3 different objects corresponding to each new word during training (High Variability group). Children completed vocabulary learning tests for objects seen during training and for new within-category objects that were never seen during training as a test of category generalization. Learning was assessed the day after each training activity, and retention was assessed 3 weeks after the last training session.
Results
There were no group differences on trained or generalization items immediately following training sessions. However, children in the High Variability group demonstrated significantly better retention 3 weeks after experimental training.
Conclusion
These findings demonstrate that object variability facilitates retention of new word learning by children with SLI.
Supplemental Material
https://doi.org/10.23641/asha.5583979
... For example, visual variability encountered across target stimuli facilitates categorization in 6-to 7-month-old infants (Quinn & Bhatt, 2010), and phonological variability in affect or speaker has been shown to support early word recognition (Rost & McMurray, 2009;Singh, 2008). Recent work has shown that target variability also affects word learning: in a referent selection task, when shown a novel 3D object category with exemplars that varied in color, 30-month-old children learned category labels, but did not when exemplars were identical, or varied in shape and color simultaneously (Twomey, Ranson, & Horst, 2014; see also Ankowski, Vlach & Sandhofer, 2013;Perry, Samuelson, Malloy & Schiffer, 2010). Thus, while some target variability supports language learning, too much target variability appears Running head: BACKGROUND VARIABILITY HELPS WORD LEARNING 5 to disrupt it. ...
... Where's the apple). In line with typical 3D object referent selection tasks in which warm-up trials include ostensive Running head: BACKGROUND VARIABILITY HELPS WORD LEARNING 10 feedback (e.g., Twomey et al., 2014), during the next 3 s the target object rotated accompanied by a twinkling sound, followed by ostensive auditory feedback (e.g., There's the apple!). In the final 1 s the objects bounced diagonally towards the bottom right hand corner and offscreen, accompanied by the sound of children cheering. ...
... The variable color condition is one of the first word learning experiments to show children performing apparently poorly during referent selection but successfully at test. In typical analyses of word learning tasks with 3D objects, test trials for which children have not correctly mapped novel labels during referent selection are excluded, with the rationale that children do not learn (correct) novel label-novel object mappings when (incorrectly) mapping novel labels to known objects (e.g., Hilton & Westermann, 2016;Twomey et al., 2014). From this perspective it is surprising that children in the variable color condition were the only ones to show robust retention: if during training these children were not looking to novel objects at above-chance levels, how then did they retain? ...
Variability is prevalent in early language acquisition, however whether it supports or hinders learning is unclear: while target variability has been shown to facilitate word learning, variability in competitor items has been shown to make the task harder. Here we tested whether background variability could boost learning in a referent selection task. Two groups of two-year-old children saw arrays of one novel and two known objects on a screen, and heard a novel or known label. Stimuli were identical across conditions, with the exception that in the constant color condition objects appeared on a uniform white background, and in the variable color condition backgrounds were different, uniform colors. At test, only children in the variable condition showed evidence of retaining label-object associations. These data support findings from the adult memory literature, which suggest that variability supports learning by decontextualizing representations. We argue that these data are consistent with dynamic systems accounts of learning in which low-level entropy adds sufficient noise to the developmental system to precipitate a change in behavior.
... Similarly conflicting findings have been observed for manipulations related to exemplar variability, and facilitative effects of object exemplar variability on word learning and generalization have been reported (Ankowski et al., 2013;Gentner et al., 2007;Namy & Gentner, 2002;Nicholas et al., 2019;Perry et al., 2010;Twomey et al., 2014), but have not been consistently documented (e.g., Ankowski et al., 2013;Höhle et al., 2020;Maguire et al., 2008;Price & Sandhofer, 2021). For example, pediatric language intervention research suggests benefits of teaching new words via multiple object exemplars (Aguilar et al., 2018;Alt et al., 2014;Nicholas et al., 2019;Plante Oglivie, Vance et al., 2014). ...
... On the one hand, input variability may interfere with children's XSWL performance, in line with speech perception literature (e.g., Creel & Jimenez, 2012;Lim et al., 2019;Ryalls & Pisoni, 1997) and models of speech processing that indicate increased cognitive effort associated with multiple-speaker input (Choi & Perrachione, 2019;Lim et al., 2019). On the other hand, we also considered the possibility that input variability might enhance XSWL in line with the explicit word and category learning literatures (e.g., Gentner et al., 2007;Namy & Gentner, 2002;Perry et al., 2010;Twomey et al., 2014). ...
The present study examined whether length of bilingual experience and language ability contributed to cross-situational word learning (XSWL) in Spanish-English bilingual school-aged children. We contrasted performance in a high variability condition, where children were exposed to multiple speakers and exemplars simultaneously, to performance in a condition where children were exposed to no variability in either speakers or exemplars. Results revealed graded effects of bilingualism and language ability on XSWL under conditions of increased variability. Specifically, bilingualism bolstered learning when variability was present in the input but not when variability was absent in the input. Similarly, robust language abilities supported learning in the high variability condition. In contrast, children with weaker language skills learned more word-object associations in the no variability condition than in the high variability condition. Together, the results suggest that variation in the learner and variation in the input interact and modulate mechanisms of lexical learning in children.
... Prior research in this area has yielded mixed results. Use of multiple exemplars has been shown to facilitate word learning (Twomey et al., 2014) and generalization (Perry et al., 2010) in typically developing children and novel word retention in children with specific language impairment (Aguilar et al., 2018). It has also been suggested that using multiple exemplars in treatment may facilitate acquisition for people with primary progressive aphasia (Hoffman et al., 2015). ...
... These data suggest that this is not the case, as there was no significant main effect of group and no significant interaction between Group and Time Point. This outcome is inconsistent with studies that have found benefits to training multiple exemplars in children (Perry et al., 2010;Twomey et al., 2014) and for some people with semantic dementia (Hoffman et al., 2015) but is consistent with a prior study that found no effect of stimulus variability in aphasia treatment . It may be that children and those with semantic dementia have weaker or less-specified semantic representations, so having multiple training exemplars supports them in developing robust lexical-semantic representations and connections; in contrast, those with stroke-induced aphasia generally have relatively intact semantic representations and, therefore, do not benefit in this way. ...
Introduction
Repetition priming can lead to improved naming ability in people with aphasia, but concerns have arisen from prior research about using only a single picture exemplar for each target. Specifically, it is unclear whether the observed improvements were due to learning simple correspondences between particular words and pictures rather than changes at a deeper level of lexical–semantic processing. In addition, implications for generalization after training with single exemplars were unclear. This study replicated and extended previous work to address these questions.
Method
Five participants with chronic aphasia participated in this repeated-measures design study, which repeatedly paired words and pictures with no feedback provided. Two participants engaged in a single-exemplar condition, with a single picture exemplar of each target used for every presentation of that target. The remaining three participants engaged in a multiple-exemplar condition, with several different pictures used for each target. Half of these targets used training pictures during naming probes, whereas half did not.
Results
Primed items led to greater improvements in naming than items that were practiced but not primed. The data indicate that improvements may extend beyond stimulus-specific correspondences. Maintenance and generalization effects were mixed.
Conclusions
These data provide further support for the efficacy of repetition priming treatment for anomia. Implications and future directions are discussed.
... Studies have shown that children as young as 3 months can accommodate exemplar variability and construct categories for unfamiliar objects when exposed to varying exemplars (e.g., Bornstein & Mash, 2010). Many empirical studies have demonstrated that exemplar variability supports children's explicit word learning, category learning, and generalization (e.g., Ankowski et al., 2013;Gentner et al., 2007;Namy & Gentner, 2002;Perry et al., 2010;Twomey et al., 2014). In treatment studies, findings suggest that incorporating object variability into language intervention improves children's retention of newly learned words (Aguilar et al., 2018;Alt et al., 2014;Nicholas et al., 2019). ...
... Our findings also suggest that XSWL may be insensitive to exemplar variability effects, at least as manipulated here. One possibility is that facilitative effects of multiple exemplar exposure observed in the explicit word learning literature (e.g., Ankowski et al., 2013;Gentner et al., 2007;Namy & Gentner, 2002;Perry et al., 2010;Twomey et al., 2014; but see Höhle et al., 2020) and in language intervention studies designed on principles of statistical learning (e.g., Aguilar et al., 2018;Alt et al., 2014;Nicholas et al., 2019) might not extend to experimental statistical learning paradigms. However, facilitative effects of exemplar variability were plausible given recent evidence showing that children aged 7 to 9 years are sensitive to feature regularities that define visual objects (Broedelet et al., 2022). ...
In the current study, we examined the separate and combined effects of exemplar and speaker variability on monolingual and bilingual children's cross-situational word learning performance. Results revealed that children's word learning performance did not differ when the input varied in a single dimension (i.e., exemplars or speakers) compared with a condition with no variability independent of their linguistic background. However, when performance in conditions that varied in a single dimension (i.e., exemplars or speakers) was compared with a condition that varied in multiple dimensions (i.e., exemplars and speakers), bilingual word learning advantages were observed; bilinguals were more likely to learn word-referent associations than monolinguals. Together, results suggest that children can learn and generalize word-referent associations from input that varies in exemplars and speakers and that bilingualism may bolster learning under conditions of increased input variability.
... For example, in a longitudinal training study, Perry and colleagues demonstrated that training 18-month-old children with variable exemplars of categories of objects supported them in more successfully generalizing new words to unfamiliar exemplars, and led to increases in vocabulary development relative to peers who saw the same object repeatedly (Perry et al., 2010). Further research has shown that two-year-old children who were taught novel category names by exposing them to variable exemplars of objects from the same category were able to retain more novel category names than children who were exposed to single exemplars only (Twomey et al., 2014). Thus, exposing children to multiple, variable exemplars rather than only one category member may provide children with the opportunity to compare similar features of each of the exemplars, and, therefore, facilitate word learning for that category. ...
... Thus, exposing children to multiple, variable exemplars rather than only one category member may provide children with the opportunity to compare similar features of each of the exemplars, and, therefore, facilitate word learning for that category. However, when exemplar variability was too high, that is, exemplars differed on multiple characteristics (shape, size, colour, etc), word learning was hindered (Twomey et al., 2014). Twomey and colleagues explained this finding by suggesting that when exemplar variability is high, more attentional resources are required, leaving fewer for committing the word-object associations to memory. ...
Although strong claims have been made about museums being ideal word learning environments, these are yet to be empirically supported. In the current study, 152 four‐ to five‐year‐olds children (81‐M, 71‐F) from minority backgrounds were taught six vocabulary items either in a museum, in their classroom with museum resources, or in their classroom with classroom resources. At test, children taught in their classroom with museum resources produced significantly more correct responses than children taught in the museum or in their classroom with classroom resources. Children were also significantly better at retaining the target vocabulary items than recalling them. These data demonstrate how context can impact word learning and point to the benefits of a collaborative relationship between schools and museums to support children's language development.
... Early knowledge transfer literature suggested that increasing the number and variability of exemplars can benefit learning and generalization (Gick & Holyoak, 1987 for a summary). Similarly, the developmental literature (e.g., Aguilar et al., 2018;Perry et al., 2010;Twomey et al., 2014) and applied behavioral analysis (e.g., Stokes & Baer, 1977;Stokes & Osnes, 2016;Swan et al., 2016) recommend the use of multiple exemplars to promote learning and generalization. Based on some of these findings, Thompson (1989) suggested that training multiple examples might promote generalization in aphasia. ...
... In contrast, in the high exemplar variability condition, each item was trained using three picture exemplars. This was intended to increase stimuli variability and promote within-level generalization (e. g., Aguilar et al., 2018;Perry et al., 2010;Twomey et al., 2014). In the verbal description condition, each item was trained by presenting a short verbal description prompt in both written and auditory formats. ...
Introduction
: There is a pressing need to improve computer-based treatments for aphasia to increase access to long-term effective evidence-based interventions. The current single case design incorporated two learning principles, adaptive distributed practice and stimuli variability, to promote acquisition, retention, and generalization of words in a self-managed computer-based anomia treatment.
Methods
: Two participants with post-stroke aphasia completed a 12-week adaptive distributed practice naming intervention in a single-case experimental design. Stimuli variability was manipulated in three experimental conditions: high exemplar variability, low exemplar variability, and verbal description prompt balanced across 120 trained words. Outcomes were assessed at 1-week, 1-month, and 3-months post-treatment. Statistical comparisons and effect sizes measured in the number of words acquired, generalized, and retained were estimated using Bayesian generalized mixed-effect models.
Results
: Participants showed large and robust acquisition, generalization, and retention effects. Out of 120 trained words, participant 1 acquired ∼77 words (trained picture exemplars) and ∼63 generalization words (untrained picture exemplars of treated words). Similarly, participant 2 acquired ∼57 trained words and ∼48 generalization words. There was no reliable change in untrained control words for either participant. Stimuli variability did not show practically meaningful effects.
Conclusions
: These case studies suggest that adaptive distributed practice is an effective method for re-training more words than typically targeted in anomia treatment research (∼47 words on average per Snell et al., 2010). Generalization across experimental conditions provided evidence for improved lexical access beyond what could be attributed to simple stimulus-response mapping. These effects were obtained using free, open-source flashcard software in a clinically feasible, asynchronous format, thereby minimizing clinical implementation barriers. Larger-scale clinical trials are required to replicate and extend these effects.
... Variability among instances of visual forms is a known driver of category learning (e.g. Perry, Samuelson, Malloy, & Schiffer, 2010;Twomey, Lush, Pearce, & Horst, 2014;Twomey, Ranson, & Horst, 2014). Compared to typeface letters, handwritten letters are variable in form-each production of a letter is different from the last-especially when produced by young children (Longstaff & Heath, 1997;Wing & Nimmo-Smith, 1987). ...
... This visual input may be responsible for the changes in ventral-temporal function after letter production. Ventral-temporal cortex is broadly associated with object categorization processes (for review, see Grill-Spector & Weiner, 2014), and the development of object categorization processes is largely driven by the perceptual differentiation that follows exposure to category variability (Li & James, 2016;Perry et al., 2010;Twomey, Lush, et al., 2014;Twomey, Ranson, et al., 2014). Our results suggest that ventral-temporal cortex may be most sensitive to the variability present in handwritten forms when children are first learning about letters and that this sensitivity to visual variability may be a part of how ventral-temporal cortex undergoes developmental changes that contribute to the formation of category-specific responses. ...
Letter production through handwriting creates visual experiences that may be important for the development of visual letter perception. We sought to better understand the neural responses to different visual percepts created during handwriting at different levels of experience. Three groups of participants, younger children, older children, and adults, ranging in age from 4.5 to 22 years old, were presented with dynamic and static presentations of their own handwritten letters, static presentations of an age‐matched control's handwritten letters, and typeface letters during fMRI. First, data from each group were analyzed through a series of contrasts designed to highlight neural systems that were most sensitive to each visual experience in each age group. We found that younger children recruited ventral‐temporal cortex during perception and this response was associated with the variability present in handwritten forms. Older children and adults also recruited ventral‐temporal cortex; this response, however, was significant for typed letter forms but not variability. The adult response to typed letters was more distributed than in the children, including ventral‐temporal, parietal, and frontal motor cortices. The adult response was also significant for one's own handwritten letters in left parietal cortex. Second, we compared responses among age groups. Compared to older children, younger children demonstrated a greater fusiform response associated with handwritten form variability. When compared to adults, younger children demonstrated a greater response to this variability in left parietal cortex. Our results suggest that the visual perception of the variability present in handwritten forms that occurs during handwriting may contribute to developmental changes in the neural systems that support letter perception.
... Variability among instances of visual forms is a known driver of category learning (e.g. Perry, Samuelson, Malloy, & Schiffer, 2010;Twomey, Lush, Pearce, & Horst, 2014;Twomey, Ranson, & Horst, 2014). Compared to typeface letters, handwritten letters are variable in form-each production of a letter is different from the last-especially when produced by young children (Longstaff & Heath, 1997;Wing & Nimmo-Smith, 1987). ...
... This visual input may be responsible for the changes in ventral-temporal function after letter production. Ventral-temporal cortex is broadly associated with object categorization processes (for review, see Grill-Spector & Weiner, 2014), and the development of object categorization processes is largely driven by the perceptual differentiation that follows exposure to category variability (Li & James, 2016;Perry et al., 2010;Twomey, Lush, et al., 2014;Twomey, Ranson, et al., 2014). Our results suggest that ventral-temporal cortex may be most sensitive to the variability present in handwritten forms when children are first learning about letters and that this sensitivity to visual variability may be a part of how ventral-temporal cortex undergoes developmental changes that contribute to the formation of category-specific responses. ...
... In contrast, 10-month-old infants in a categorization task formed a robust category when familiarized with novel stimuli in an order that maximized, but not minimized, overall perceptual differences between successive stimuli (Mather & Plunkett, 2011). Still other studies have uncovered a "Goldilocks" effect in which learning is optimal when stimuli are of intermediate predictability (Kidd et al., 2012(Kidd et al., , 2014; see also Kinney & INFANT CURIOSITY: A NEUROCOMPUTATIONAL APPROACH 9 Kagan, 1976;Twomey, Ranson, & Horst, 2014). From this perspective, the degree of novelty and/or complexity in the environment that best supports learning is unclear. ...
... best support learning (Kidd et al., 2012(Kidd et al., , 2014Kinney & Kagan, 1976;Twomey et al., 2014). Equally, simplicity has been shown to support learning in some cases (Bulf et al., 2011;Son, Smith, & Goldstone, 2008). ...
Infants are curious learners who drive their own cognitive development by imposing structure on their learning environment as they explore. Understanding the mechanisms by which infants structure their own learning is therefore critical to our understanding of development. Here we propose an explicit mechanism for intrinsically motivated information selection that maximizes learning. We first present a neurocomputational model of infant visual category learning, capturing existing empirical data on the role of environmental complexity on learning. Next we “set the model free”, allowing it to select its own stimuli based on a formalization of curiosity and three alternative selection mechanisms. We demonstrate that maximal learning emerges when the model is able to maximize stimulus novelty relative to its internal states, depending on the interaction across learning between the structure of the environment and the plasticity in the learner itself. We discuss the implications of this new curiosity mechanism for both existing computational models of reinforcement learning and for our understanding of this fundamental mechanism in early development.
... In the present study, we focus on a learning design, the comparison design, which has been shown to facilitate category learning and novel word generalization when salient similarities (e.g., such as shape) lack conceptual relevance while the similarities unifying the category (e.g., texture similarities) are a priori less salient (Alfieri et al., 2013;Augier and Thibaut, 2013;Gentner and Namy, 1999;Namy and Clepper, 2010;Price and Sandhofer, 2021;Stansbury et al., 2024;Thibaut and Witt, 2023;Twomey et al., 2014). Indeed, a large body of recent studies shows that comparing two or more learning stimuli leads to more conceptually based generalizations [e.g., taxonomically-based versus perceptually-based], of novel words than single stimulus learning condition (see Imai et al., 1994). ...
Numerous studies have shown that in novel noun generalization tasks, the simultaneous presentation of multiple learning examples increases the percentage of generalizations that are based on a priori less salient properties, compared to the presentation of a single learning example. In this research with preschoolers (n = 300) we demonstrate that this effect can be modulated by dimensional distinctiveness, i.e., how easy it is to determine whether two dimension values (shape and 2D texture) are easy to distinguish or not. In a first experiment, we manipulate dimensional distinctiveness globally (both shape and 2D texture are distinctive, or not) and explore how it interacts with comparisons format: two learning examples from the same category (i.e., within-category comparison), two learning examples from different categories (i.e., between-category comparison), and no-comparison (i.e., only one learning example). Results show that within-category comparisons yielded more taxonomic generalizations than between-category comparisons and no-comparison conditions. Furthermore, children selected more often the taxonomic match with highly distinctive stimuli than with low distinctive stimuli. In a second experiment, we independently manipulate the distinctiveness of stimuli shape and 2D texture to determine which dimension distinctiveness might contribute to better generalization in a within-comparison format. Results indicated that within-category comparisons resulted in more taxonomic generalization with distinctive textures, regardless of shape distinctiveness. These findings suggest that not all comparison conditions are equals and that children’s generalizations may be influenced by the characteristics of the stimuli.
... effect size f2 = .25 based on Horst et al., 2020;Twomey et al., 2014) revealed that 72 participants were needed (but see below for power with extra predictors). The final sample included 72 typically developing monolingual children (34 girls, 38 boys, M age = 30.28 ...
The current study investigates whether children's attempts to solve referential ambiguity is best explained as a process-of-elimination or a novelty bias. We measured 2.5-year-old children's pointing and eye movements during referent selection trials and assessed whether this changes across repeated exposures. We also tested children's retention of novel words and how much focusing on novel targets during referent selection supports immediate and delayed retention as well as the effect of hearing the words ostensively named after referent selection. Time course analyses of children's looking during referent selection indicated that soon after noun onsets, in familiar target trials there was a greater focus on targets relative to chance, but in novel target trials, children focussed on targets less than chance, suggesting an initial focus on competitors. Children also took longer to focus on and point to novel compared to familiar targets. Thus, this converging evidence suggests referent selection is best described as a process-of-elimination. Ostensive naming also led to faster pointing at novel targets in subsequent trials and better delayed retention than the non-ostensive condition. In addition, a greater focus on novel targets during referent selection was associated with better immediate retention for the ostensive naming condition, but better delayed retention for the non-ostensive condition. Therefore, a focus on novelty may supplement weaker encoding, facilitating later retention.
... For each session, each object was presented twice, but with two different exemplars (e.g., two different toy cars) for each object, because varying exemplars have been found to facilitate word learning (40). There was no significant difference between the 1st and 2nd presentation of a similar object, however (mean performance for the 1st presentation = 0.10, SD = 0.13; 2nd presentation, M = 0.035, SD = 0.18; t(32) = 1.64, ...
We know little about the mechanisms through which leader–follower dynamics during dyadic play shape infants’ language acquisition. We hypothesized that infants’ decisions to visually explore a specific object signal focal increases in endogenous attention, and that when caregivers respond to these proactive behaviors by naming the object it boosts infants’ word learning. To examine this, we invited caregivers and their 14-mo-old infants to play with novel objects, before testing infants’ retention of the novel object-label mappings. Meanwhile, their electroencephalograms were recorded. Results showed that infants’ proactive looks toward an object during play associated with greater neural signatures of endogenous attention. Furthermore, when caregivers named objects during these episodes, infants showed greater word learning, but only when caregivers also joined their focus of attention. Our findings support the idea that infants’ proactive visual explorations guide their acquisition of a lexicon.
... Specifically, researchers have been interested in identifying how children remember words across time (Horst and Samuelson, 2008;Kucker and Samuelson, 2012;Vlach, 2019). This work has revealed that characteristics of the learning environment can influence the degree to which children remember words (e.g., Vlach et al., 2008;Vlach and Sandhofer, 2012;Twomey et al., 2014). ...
Introduction
Retrieval practice enhances adults' long-term memory over restudying. However, it is less clear whether young children also benefit from retrieval practice. This study assessed whether retrieval practice could support children's novel word learning in the context of storybook reading.
Method
In Experiments 1–3, preschoolers ( N = 167, Range Age = 26–68 months) were presented with 10 novel word-object pairs across four consecutive storybook readings. Half of the children were read the storybook four times (i.e., SSSS), whereas the other half of the children were read the storybook once and were then asked to retrieve the novel words during the subsequent three readings (i.e., STTT). Children's recall and recognition memory for the novel words was tested after a 5-min delay.
Results and discussion
Results revealed that although children had high retrieval success during learning, retrieval practice did not provide an advantage over re-reading for children's recall (Experiment 1), even when additional mapping and retrieval opportunities were provided (Experiment 2); that is, children who engaged in retrieval practice did not outperform children who re-read the storybooks. A retrieval practice effect also did not emerge in children's recognition memory of novel words (Experiment 3). Taken together, this study suggests that retrieval practice may only benefit young children under specific learning conditions. Future research should therefore consider characteristics of the learner and broader learning context to explain developmental differences in retrieval practice effects.
... The ability to form new conceptual knowledge is a key function of memory, allowing individuals to organize past experiences and apply them efficiently to new situations. How to tailor learning to best promote acquisition of new conceptual knowledge has been a question of considerable interest not only in cognitive psychology (Hahn et al., 2005;Mervis & Pani, 1980;Williams & Lombrozo, 2010), but also in domains like child development (Ogren & Sandhofer, 2021;Perry et al., 2010;Twomey et al., 2014), linguistics (Bulgarelli & Weiss, 2019;Onnis et al., 2004;Plante et al., 2014), and computer science (Hart, 1968;Hernandez-Garcia & König, 2020;Roiger & Cornell, 1996;Zhou et al., 2017). The answer to this question has practical implications for how instructors select training examples to maximize the generalizability of learning. ...
A major question for the study of learning and memory is how to tailor learning experiences to promote knowledge that generalizes to new situations. In two experiments, we used category learning as a representative domain to test two factors thought to influence the acquisition of conceptual knowledge: the number of training examples (set size) and the similarity of training examples to the category average (set coherence). Across participants, size and coherence of category training sets were varied in a fully crossed design. After training, participants demonstrated the breadth of their category knowledge by categorizing novel examples varying in their distance from the category center. Results showed better generalization following more coherent training sets, even when categorizing items furthest from the category center. Training set size had limited effects on performance. We also tested the types of representations underlying categorization decisions by fitting formal prototype and exemplar models. Prototype models posit abstract category representations based on the category’s central tendency, whereas exemplar models posit that categories are represented by individual category members. In Experiment 1, low coherence training led to fewer participants relying on prototype representations, except when training length was extended. In Experiment 2, low coherence training led to chance performance and no clear representational strategy for nearly half of the participants. The results indicate that highlighting commonalities among exemplars during training facilitates learning and generalization and may also affect the types of concept representations that individuals form.
... Early categorization skills are strongly implicated in the ability to acquire the labels of referents (Gelman & Markman, 1986;Markman, 1989;Twomey et al., 2014). Categorization skills have not been extensively studied across the autism spectrum and across dimensions of language ability. ...
Word learning requires successful pairing of form and meaning. A common hypothesis about the process of word learning is that initially, infants work on identifying the phonological segments corresponding to words (speech analysis), and subsequently map those segments onto meaning. A range of theories have been proposed to account for the underlying mechanisms and factors in this remarkable achievement. While some are mainly concerned with the sensorimotor affordances and perceptual properties of referents out in the world, other theories emphasize the importance of language as a system, and the relations among language units (other words or syntax). Recent approaches inspired by neuro-science suggest that the storage and processing of word meanings is supported by neural systems subserving both the representation of conceptual knowledge and its access and use (Lambon Ralph et al., Nature Reviews Neuroscience 18:42–55, 2017). Developmental disorders have been attested to impact on different aspects of word learning. While impaired word knowledge is not a hallmark of Autism Spectrum Disorder (ASD), and remains largely understudied in this population, there is evidence that there are, sometimes subtle, problems in that domain, reflected in both how such knowledge is acquired and how words are used (Vulchanova et al., Word knowledge and word usage: A cross-disciplinary guide to the mental lexicon, Mouton De Gruyter, 2020). In addition, experimental evidence suggests that children with autism present with specific problems in categorizing the referents of linguistic labels leading to subsequent problems with using those labels (Hartley and Allen, Autism 19:570–579, 2015). Furthermore, deficits have been reported in some of the underlying mechanisms, biases and use of cues in word learning, such as e.g., object shape (Field et al., Journal of Autism and Developmental Disorders 46:1210–1219, 2016; Tek et al., Autism Research 1:208–222, 2008). Finally, it is likely that symbol use might be impaired in ASD, however, the direction of the causal relationship between social and communication impairment in autism and symbolic skills is still an open question (Allen and Lewis, Journal of Autism and Developmental Disorders 45:1–3, 2015; Allen and Butler, British Journal of Developmental Psychology 38:345–362, 2020; Wainwright et al., Journal of Autism and Developmental Disorders 50:2941–2956, 2020). Further support for impaired symbol formation in autism comes from the well-attested problems with figurative, non-literal language use (e.g., metaphors, idioms, hyperbole, irony) (Vulchanova et al., Frontiers in Human Neuroscience 9:24, 2015). Here we propose that embodied theories of cognition which link perceptual experience with conceptual knowledge (see Eigsti, Frontiers in Psychology 4:224, 2013; Klin et al., Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences 358:345–360, 2003) might be useful in explaining the difficulty in symbolic understanding that individuals with autism face during the word learning process.
... There are similar findings in the second language literature, where there is evidence that encountering varying talkers can assist in auditory and speech perception tasks and robust vocabulary learning (Strange and Dittmann, 1984;Logan et al., 1991;Lively et al., 1993;Clopper and Pisoni, 2004;Barcroft and Sommers, 2005;Sinkeviciute et al., 2019). More opportunity to compare across multiple exemplars has also been found to boost memory of novel words in child language: In Twomey et al. (2014), 2-year-olds presented with multiple exemplars of a category demonstrated better retention of label-object associations than children who only encountered the same exemplar repeatedly. The authors argue that children who encountered multiple exemplars retained words at greater rates because the act of comparing exemplars across trials enabled children to identify category-relevant features while downplaying categoryirrelevant features. ...
Human language is characterized by productivity, that is, the ability to use words and structures in novel contexts. How do learners acquire these productive systems? Under a discriminative learning approach, language learning involves using cues to predict and discriminate linguistic outcomes and “generalization” involves dissociating idiosyncratic irrelevant cues in favour of informative, invariant cues. The current work tests the predictions of this account using the learning of spatial adpositions as a test case. Spatial adpositions describe the location of one object in relation to another (e.g., English prepositions “above'' and “below'') and may occur in reversible sentences, such as "the picture is above the window"; generalization involves using these terms in novel contexts, such as with unattested nouns. Computational simulations implementing an error-driven, discriminative learning process, demonstrate that broadening the irrelevant cues associated with the stimuli may boost the discovery of invariant cues, i.e., the association between the adposition and the spatial relation. We explore the predictions of these models in human learners by adapting a training paradigm introduced by Hsu and Bishop (2014) to teach typically-developing 7/8 year olds spatial adpositions in an unfamiliar language (Japanese) using a computerized learning game. We manipulate the cue variability by comparing groups of children trained with more variable sentences (high variability) with a condition with repetition of the same sentences (low variability). A third condition (skew) tests whether learning and generalization are boosted when learning from a heavy tailed distribution that more closely resembles that of natural language. We will examine the following predictions: (1) for sentences with novel nouns, participants trained with variable sentences will show better performance (i.e., stronger generalization) than those trained with repeated sentences; (2) in contrast, those trained with repeated sentences will show stronger performance in training itself (i.e., stronger item learning); (3) training with a heavy tailed distribution -- more closely resembling the natural one -- will lead to the strongest item learning and generalization.
... This view is also supported by research on noun learning and categorization. An exposure to variable exemplars helps children learn and retain novel labels (Perry, Samuelson, Malloy, & Schiffer, 2010;Twomey, Ranson, & Horst, 2014). In addition, seeing a broad range of exemplars facilitates children's formation and generalization of nonlinguistic and linguistic categories of geometric shapes (Bomba & Siqueland, 1983), categories of objects (Gentner & Namy, 1999;Graham, Namy, Gentner, & Meagher, 2010;Oakes & Spalding, 1997), perceptual organization (Bhatt & Quinn, 2011), and non-adjacent dependencies of 3-element strings (e.g., aXc or bXd - Gomez, 2002). ...
Verbs serve as the architectural centerpiece of sentences, making verb learning pivotal for language acquisition. Verb learning requires both the formation of a verb-action mapping and the abstraction of relations between an object and its action. Two competing positions have been proposed to explain the process of verb learning: (a) seeing a highly variable range of exemplars allows children to detect and abstract the commonalities across actions—the action invariants; and (b) seeing a less variable range of exemplars enables children to focus on and extract the action invariants. Using manner—a major component of verb meaning in English—as a test case, this study addressed this debate by examining the influence of manner variability on the ability to fast-map new verbs and extend them to novel exemplars in 2-, 3-, and 4-year-old English-speaking children. Results contribute to this debate by showing that high manner variability hindered fast-mapping but facilitated extension to manner variations in the 2- and 3-year-olds. Thus, high exemplar variability may affect verb fast-mapping and extension differently. Furthermore, manner variability did not affect 4-year-olds’ (or adults’) fast-mapping or extension, suggesting that the influence of exemplar variability on verb learning attenuates with age. Finally, manner variability did not affect agent or object extension, revealing a component-specific effect of exemplar variability on verb extension.
... In general, high variability can make learning more difficult when learners are in the very early stages of acquiring a target behavior. For instance, beginners and children who are only just 'getting the hang' of a motor skill (e.g., a tennis serve) or who are just being familiarized with a novel category benefit from low variability during initial practice (e.g., blocked training as opposed to more variable interleaved training; exposure to exemplars with little to no variation between them), and may experience difficulties or even get overwhelmed when too much variability is introduced at first [55,71,[74][75][76][77][78][79]. For example, students with less prior knowledge who are learning to solve math problems benefit from receiving less variable examples first, while the opposite is true for students with more prior knowledge [63,80]. ...
Learning is using past experiences to inform new behaviors and actions. Because all experiences are unique, learning always requires some generalization. An effective way of improving generalization is to expose learners to more variable (and thus often more representative) input. More variability tends to make initial learning more challenging, but eventually leads to more general and robust performance. This core principle has been repeatedly rediscovered and renamed in different domains (e.g., contextual diversity, desirable difficulties, variability of practice). Reviewing this basic result as it has been formulated in different domains allows us to identify key patterns, distinguish between different kinds of variability, discuss the roles of varying task-relevant versus irrelevant dimensions, and examine the effects of introducing variability at different points in training.
... However, in real life, people choose to obtain information from more than one person. Furthermore, many studies have shown that children with multiple learning samples have better word learning abilities compared to those who learn from only one sample [36][37][38]. For this reason, we choose GB and RB i as the two examples of the ith particle social learning part in this study. ...
In the traditional particle swarm optimization algorithm, the particles always choose to learn from the well-behaved particles in the population during the population iteration. Nevertheless, according to the principles of particle swarm optimization, we know that the motion of each particle has an impact on other individuals, and even poorly behaved particles can provide valuable information. Based on this consideration, we propose Lévy flight-based inverse adaptive comprehensive learning particle swarm optimization, called LFIACL-PSO. In the LFIACL-PSO algorithm, First, when the particle is trapped in the local optimum and cannot jump out, inverse learning is used, and the learning step size is obtained through the Lévy flight. Second, to increase the diversity of the algorithm and prevent it from prematurely converging, a comprehensive learning strategy and Ring-type topology are used as part of the learning paradigm. In addition, use the adaptive update to update the acceleration coefficients for each learning paradigm. Finally, the comprehensive performance of LFIACL-PSO is measured using 16 benchmark functions and a real engineering application problem and compared with seven other classical particle swarm optimization algorithms. Experimental comparison results show that the comprehensive performance of the LFIACL-PSO outperforms comparative PSO variants.
... The importance of perceptual variability during learning is not a new hypothesis. Indeed, according to several studies, comparison would play a critical role in the categorization of novel objects (e.g., Gentner and Namy, 1999;Namy and Gentner, 2002;Graham et al., 2010;Twomey et al., 2014). Some studies even suggested that the greater the variability among exemplars during learning, the better the generalization to new category instances (Posner and Keele, 1968;Perry et al., 2010). ...
Based on evidence that learning new characters through handwriting leads to better recognition than learning through typing, some authors proposed that the graphic motor plans acquired through handwriting contribute to recognition. More recently two alternative explanations have been put forward. First, the advantage of handwriting could be due to the perceptual variability that it provides during learning. Second, a recent study suggests that detailed visual analysis might be the source of the advantage of handwriting over typing. Indeed, in that study, handwriting and composition –a method requiring a detailed visual analysis but no specific graphomotor activity– led to equivalent recognition accuracy, both higher than typing. The aim of the present study was to assess whether the contribution of detailed visual analysis is observed in preschool children and to test the variability hypothesis. To that purpose, three groups of preschool children learned new symbols either by handwriting, typing, or composition. After learning, children performed first a four-alternative recognition task and then a categorization task. The same pattern of results as the one observed in adults emerged in the four-alternative recognition task, confirming the importance of the detailed visual analysis in letter-like shape learning. In addition, results failed to reveal any difference across learning methods in the categorization task. The latter results provide no evidence for the variability hypothesis which would predict better categorization after handwriting than after typing or composition.
... consistencies to bootstrap audiovisual learning over multiple exposures. Our findings are in line with the regularity principle of statistical learning (Perry et al., 2010;Vlach and Sandhofer, 2011;Twomey et al., 2014), in which the cognitive system structures inherent environmental variability by integrating frequently occurring items by their co-occurrence, or consistency. This enables us to build supraordinate categories for words, and parts of words in the lexicon, and associated semantic webs. ...
Learning to read involves efficient binding of visual to auditory information. Aberrant cross-modal binding skill has been observed in both children and adults with developmental dyslexia. Here, we examine the contribution of episodic memory to acquisition of novel cross-modal bindings in typical and dyslexic adult readers. Participants gradually learned arbitrary associations between unfamiliar Mandarin Chinese characters and English-like pseudowords over multiple exposures, simulating the early stages of letter-to-letter sound mapping. The novel cross-modal bindings were presented in consistent or varied locations (i.e., screen positions), and within consistent or varied contexts (i.e., co-occurring distractor items). Our goal was to examine the contribution, if any, of these episodic memory cues (i.e., the contextual and spatial properties of the stimuli) to binding acquisition, and investigate the extent to which readers with and without dyslexia would differ in their reliance on episodic memory during the learning process. Participants were tested on their ability to recognize and recall the bindings both during training and then in post-training tasks. We tracked participants’ eye movements remotely with their personal webcams to assess whether they would re-fixate relevant empty screen locations upon hearing an auditory cue—indicative of episodic memory retrieval—and the extent to which the so-called “looking-at-nothing behavior” would modulate recognition of the novel bindings. Readers with dyslexia both recognized and recalled significantly fewer bindings than typical readers, providing further evidence of their persistent difficulties with cross-modal binding. Looking-at-nothing behavior was generally associated with higher recognition error rates for both groups, a pattern that was particularly more evident in later blocks for bindings encoded in the inconsistent location condition. Our findings also show that whilst readers with and without dyslexia are capable of using stimulus consistencies in the input—both location and context—to assist in audiovisual learning, readers with dyslexia appear particularly reliant on consistent contextual information. Taken together, our results suggest that whilst readers with dyslexia fail to efficiently learn audiovisual binding as a function of stimulus frequency, they are able to use stimulus consistency—aided by episodic recall—to assist in the learning process.
... In relation to the linguistic context and variability of the input, most work has been conducted with typically developing children and findings are mixed. Some have reported positive word learning effects using high referent variability with young typically developing children (Perry et al., 2010), whereas other studies suggest that too much variability (across a number of features) can have a negative effect (Twomey et al., 2013). The impact of variability is also thought to be target dependent such that noun learning might be particularly enhanced by increased variability, but verb learning less so (Gómez, 2002;Maguire et al., 2008). ...
Purpose
The aim of this study was to extract key learning from intervention studies in which qualitative aspects of dosage, dose form, have been examined for children with developmental language disorder (DLD)—in vocabulary, morphosyntax, and phonology domains. This research paper emerged from a pair of systematic reviews, aiming to synthesize available evidence regarding qualitative and quantitative aspects of dosage. While quantitative aspects had been experimentally manipulated, the available evidence for dose form (tasks or activities within which teaching episodes are delivered) was less definitive. Despite this, the review uncovered insights of value to DLD research.
Method
A preregistered systematic review (PROSPERO ID: CRD42017076663) adhering to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines was completed. Included papers were quasi-experimental, randomized controlled trial, or cohort analytic studies, published in any language between January 2006 and May 2019; oral language interventions with vocabulary, morphosyntax, or phonology outcomes; and participants with DLD (M = 3–18 years). The intention was to include papers in which dose form was experimentally manipulated or statistically analyzed, while quantitative dosage aspects were controlled, such that definitive conclusions about optimal dose form could be drawn and gaps in the evidence identified.
Results
Two hundred and twenty-four papers met the above inclusion criteria; 27 focused on dose form. No study controlled for all quantitative aspects of dosage such that we could effectively address our original research questions. Despite this, key points of learning emerged with implications for future research.
Conclusions
There is tentative evidence of advantages for explicit over implicit instruction and of the benefits of variability in input, elicited production, and gestural and other visual supports. With careful design of dose form, there is potential to design more efficient interventions. Speech-language pathology research would benefit from an agreed taxonomy of dose form components and standardized reporting of intervention studies, to enable cross-study comparisons and a systematic accrual of knowledge to identify optimal dose form for clinical application.
... While these are not necessarily explicit steps the child thinks about, they do represent a real-time competition in which the child must sort through the relevant and irrelevant information relatively quickly. This competition is driven by a number of factors including the number of competitors (Axelsson et al., 2012;Zosh, Brinster, & Halberda, 2013), novelty of the targets and foils (Horst, Samuelson, Kucker, & McMurray, 2011;Kucker, McMurray, & Samuelson, 2018), saliency of known foils (Pomper & Saffran, 2019), the child's current vocabulary knowledge (Bion, Borovsky, & Fernald, 2013;Kucker, McMurray, & Samuelson, 2020), pragmatic cues such as pointing or joint attention (Tomasello, Strosberg, & Akhtar, 1996), and the repetition (Horst, 2013) and variability (Twomey, Ranson, & Horst, 2014) of the items present. These factors can all be present in a variety of contexts, but what specific processes are prominent may vary across children and environments. ...
Word learning unfolds over multiple, cascading pathways which support in-the-moment processing and learning. The process is refined with each exposure to a word, and exposures to new words occur across a variety of forms and contexts. However, as children are exposed to more and more digital media, the ways in which children encounter, learn, and build on their vocabulary is also shifting. These shifts represent changes in context, content, and at the level of the child that can lead to negative outcomes. Less work, however, has discussed what these differences mean for how things change in the underlying developmental cascade and learning processes. Here, we suggest that the increasing presence of digital media may shift the developmental pathways for learning (the chain of events that support future learning) but not necessarily the developmental processes (the mechanisms underlying learning). Moreover, the interaction of the two may lead to different behavior and outcomes for learning in a digital era. We argue it is imperative for researchers to not only study how digital media differs from everyday learning, but directly measure if the well-worn pathways, processes, and variables found with decades of research with real items translate to a digital media era.
... "car") and potentially prompting shape-based generalization to additional exemplars (e.g. green cars; Allen, Hartley, & Cain, 2015Twomey, Ranson, & Horst, 2014). Exploring the efficacy and benefits of such training would be an interesting topic for future research. ...
... Des travaux récents offrent ainsi de mieux comprendre le rôle de l'intérêt pour la nouveauté et de l'intérêt pour l'inattendu comme moteurs d'apprentissage. Il a par exempleété observé que l'apprentissage d'une nouvelle catégorie d'objets chez des bébésâgés de 10 mois (Mather & Plunkett, 2011) ou d'un nouveau mot chez des bébésâgés de 2 ans (Twomey et al., 2014)était augmenté par une maximisation de la variabilité entre les items présentés aux bébés. Cette amélioration des capacités d'apprentissage pourrait, entre autres,être sous-tendue par une attention soutenue des bébés lors de la présentation d'items très différents les uns des autres, reflet de leur intérêt pour la nouveauté (Mather, 2013;Twomey & Westermann, 2018 (Begus et al., 2014), que des bébésâgés de 17 moisétaient plus attentifsà des situations leur permettant un progrès en apprentissage (ici l'apprentissage d'une nouvelle grammaire) qu'à des situations n'offrant aucun apprentissage (Gerken et al., 2011), ou encore que des bébésâgés de 20 mois demandaient de l'aideà un partenaire social lorsque cela leur permettait d'accéderà une information qu'ils ne possédaient pas pour résoudre un problème (ici, retrouver l'emplacement d'un objet caché) (Goupil et al., 2016, voir aussi Begus & Southgate, 2012, sur le rôle du pointage dans l'acquisition d'informations chez le bébé). ...
Au regard de la place croissante occupée par l'intelligence artificielle dans nos sociétés, la nécessité d'affiner notre compréhension de la notion d'apprentissage semble plus importante que jamais. S'intégrant dans une telle optique, cette thèse de doctorat cherche à mettre en lumière les mécanismes d'apprentissage permettant au bébé d'acquérir au cours de la première année de vie une utilisation appropriée et différenciée de son corps lui permettant d'interagir de manière efficace avec son environnement physique et social, ce que nous désignons ici par le terme de "savoir-fairecorporel". Le postulat au cœur de ce travail de recherche est le suivant : l'acquisition progressive du savoir-faire corporel au cours de la vie fœtale et des premiers mois de vie post-partum est sous-tendue par deux mécanismes d'apprentissage, l'exploitation de la sensibilité aux contingencessensorimotrices et la motivation intrinsèque. Ce travail de thèse explore la première partie de ce postulat, c'est-à-dire le rôle jouée par la sensibilité aux contingences sensorimotrices dans le développement du savoir-faire corporel. Afin d'investiguer cette hypothèse, ce travail de thèsese concentre dans un premier temps sur l'analyse critique des données expérimentales déjà existantes sur le sujet, à la fois en psychologie du développement et en robotique développementale. Dans un second temps, cette recherche vise à approfondir notre compréhension de l'acquisition du savoir-faire corporel à travers l'expérimentation chez le bébé âgé de moins d'un an.
... However, it is a more common phenomenon in human society that people always have multiple exemplars during their social learning process. Moreover, many studies indicate that children with multiple learning exemplars can offer a better word learning ability compared to those children who are only learning from one exemplar [2,4,37] . The simplest explanation is that an individual can extract much more useful knowledge from multiple information providers, i.e., multiple exemplars, than from a single exemplar. ...
... Despite being sensitive to visual context, younger children may also be less efficient than adults in extracting the relevant information, which may give rise to quantitative differences. Thus, younger children might require more contrast between shape pairs to extract relevant features (see Smith commentary in Marks et al., 1987) or might require more exemplars to extract or retain the relevant information (Casasola & Park, 2013;Twomey, Ranson, & Horst, 2014;cf. Maguire, Hirsh-Pasek, Golinkoff, & Brandone, 2008). ...
... Importantly, experience with a narrow range of variable exemplars is different than experience with a wide range of variable exemplars, indicating that the range of variability experienced may have different effects on subsequent recognition. Narrow-range experience improves recognition and retention, whereas wide-range experience improves generalization (Twomey & Horst, 2011;Twomey et al., 2013). Object recognition is the identification of an object and is distinct from object naming, which is the ability to assign a label to an object; object retention is the ability to recognize a previously learned object after a delay period. ...
The influence of visual-motor experiences with written symbols on pre-reading abilities, such as letter knowledge, have been shown to be facilitatory in both correlational studies on very young children and in experimental studies on older children. However, it is not known whether any fine-motor practice will create this benefit, whether it is specific to writing letters, or whether certain ages would benefit most from handwriting practice. Here, we hypothesized that immature fine-motor skill that produces variable forms may be crucial to the beneficial effects of handwriting training – predicting the younger children would benefit more from the training than older children. Preschool-aged children, ages three to five years, were divided into two experimental groups (letter-writing, digit-writing) in a 2x2x2 design: TIME (pre, post), AGE (younger, older), and CONDITION (letter-writing, digit-writing). Each group received six weeks of training. The letter-writing and digit-writing groups practiced writing letters (A-Z) or single digits (0-9), respectively, four times per week. Before and after the training period, each group received assessments targeting letter knowledge directly. We predicted that the younger age group, compared to the older age group, in the letter-writing condition would score significantly higher on the letter knowledge tasks at post-test than at pre-test and that this effect would not occur in the digit-writing group. Results demonstrated that the younger children did show a significantly greater improvement in letter recognition skills than the older age group, but this effect held for both the letter-and digit- writing groups. These results suggest, therefore, that any fine-motor practice at a young age can facilitate letter knowledge.
... In contrast, in reaching versions of the tasks 18-month-old toddlers do not perform well on reference selection or retention (Kucker, McMurray, & Samuelson, 2018), 24-month-olds perform well on reference selection, but they do not retain the mappings (Samuelson & Horst, 2008), and by 30 months of age children are good at both (see Kucker, McMurray, & Samuelson, 2015a for a review and discussion). Both reference selection and retention, however, can be influenced by a number of external and organismic factors (see e.g., Axelsson & Horst, 2014;Kalashnikova, Escudero, & Kidd, 2018;Kucker & Samuelson, 2012;Pomper & Saffran, 2018, Twomey, Ranson, & Horst, 2014. Still other research indicates that children as young as 13 months of age can map and, in some cases, retain novel word-object mappings when only one name and one object are presented at a time (Schafer & Plunkett, 1998;Woodward, Markman, & Fitzsimmons, 1994). ...
The use of global, standardized instruments is conventional among clini-cians and researchers interested in assessing neurocognitive development. Exclusively relying on these tests for evaluating effects may underestimate or miss specific effects on early cognition. The goal of this review is to identify alternative measures for possible inclusion in future clinical trials and interventions evaluating early neurocognitive development. The domains included for consideration are attention, memory, executive function , language, and socioemotional development. Although domain-based tests are limited, as psychometric properties have not yet been well-established, this review includes tasks and paradigms that have been reliably used across various developmental psychology laboratories. ARTICLE HISTORY
... For typically developing children acquiring language, it is not necessary to explain these similarities and differences. Mere exposure to multiple examples of category members and the category label is sufficient to induce the formation of a word class (Perry et al., 2010;Twomey, Ranson, & Horst, 2014;Vlach & Sandhofer, 2011). ...
Purpose
Statistical learning research seeks to identify the means by which learners, with little perceived effort, acquire the complexities of language. In the past 50 years, numerous studies have uncovered powerful learning mechanisms that allow for learning within minutes of exposure to novel language input.
Method
We consider the value of information from statistical learning studies that show potential for making treatment of language disorders faster and more effective.
Results
Available studies include experimental research that demonstrates the conditions under which rapid learning is possible, research showing that these findings apply to individuals with disorders, and translational work that has applied learning principles in treatment and educational contexts. In addition, recent research on memory formation has implications for treatment of language deficits.
Conclusion
The statistical learning literature offers principles for learning that can improve clinical outcomes for children with language impairment. There is potential for further applications of this basic research that is yet unexplored.
... Indeed, evidence suggests that word learning is particularly challenging for children when increasing amounts of perceptual information are presented. For example, children struggle to learn object names when target object categories are highly variable (Twomey, Ranson, & Horst, 2014), when target objects are presented in less predictable locations (Benitez & Smith, 2012), and with multiple combinations of extraneous objects, rather than the same combinations repeated (Axelsson & Horst, 2014). Such findings are consistent with cognitive load theory (Sweller, 1988(Sweller, , 1989, or see Paas, Renkl, & Sweller, 2003, for a review), which explains how working memory capacity is inherently limited and is especially problematic in situations with extraneous information. ...
Two experiments tested how the number of illustrations in storybooks influences 3.5‐year‐old children's word learning from shared reading. In Experiment 1, children encountered stories with two regular‐sized A4 illustrations, one regular‐sized A4 illustration, or one large‐sized A3 illustration (in the control group) per spread. Children learned significantly fewer words when they had to find the referent within two illustrations presented at the same time. In Experiment 2, a gesture was added to guide children's attention to the correct page in the 2‐illustration condition. Children who saw two illustrations with a guiding gesture learned words as well as children who had seen only one illustration per spread. Results are discussed in terms of the cognitive load of word learning from storybooks.
Highlights
This study demonstrates that the number of illustrations in storybooks influences rate of word learning.
Children who see only 1 illustration at a time learn more words from storybooks. Children who see 2 illustrations at a time do not learn words from storybooks. When a supporting gesture is added, children can learn words in the presence of 2 illustrations.
Extraneous information hinders word learning from storybooks.
... For example, visual variability encountered across stimuli facilitates categorization in 6-to 7-month-old infants (Quinn & Bhatt, 2010), and phonological variability in affect or speaker has been shown to support early word recognition (Rost & McMurray, 2009). Recent work has revealed a similar effect of variability on word learning: when shown a novel 3D object category with exemplars that varied in color, 30-month-old children learned category labels, but did not when exemplars were identical, or varied in shape and color simultaneously (Twomey, Ranson, & Horst, 2014). Thus, while some target variability supports word learning, too much variability appears to disrupt it. ...
Variability is important in language acquisition; however, whether it supports or hinders learning is unclear: while 3D object studies suggest that children learn word-object mappings better when the object varies, storybook studies indicate that variability in the context in which new objects are shown impairs learning. We tested a dynamic systems account in which background variability should boost learning by speeding the emergence of new behaviors. Two groups of two-year-old children saw arrays of one novel and two known objects on a screen, and heard a novel or known label. Stimuli were identical across conditions, with the exception that in the constant condition objects appeared on a white background, and in the variable condition backgrounds were colored. At test, only children in the variable condition showed evidence of word learning. These data suggest that extraneous variability supports learning by decontextualizing representations, and indicate that low-level entropy adds sufficient noise to the developmental system to triggger a change in behavior.
... This pattern of increased motor stability, rather than variability, during the early phases of word learning in children with ASD may be detrimental to subsequent language learning. A growing body of evidence indicates that variability during tasks of motor learning (Herzfeld & Shadmehr, 2014;James & Conatser, 2014) and language learning (Childers & Tomasello, 2001;Gomez, 2002;Richtsmeier, Gerken, Goffman, & Hogan, 2009;Twomey, Ranson, & Horst, 2014) leads to greater gains in skill learning and generalization. If children with ASD rapidly become reliant on more stable, repetitive motor patterns during tasks of word learning, they may be at a disadvantage during later stages of language learning. ...
Semantically rich learning contexts facilitate semantic, phonological, and articulatory aspects of word learning in children with typical development (TD). However, because children with autism spectrum disorder (ASD) show differences at each of these processing levels, it is unclear whether they will benefit from semantic cues in the same manner as their typical peers. The goal of this study was to track how the inclusion of rich, sparse, or no semantic cues influences semantic, phonological, and articulatory aspects of word learning in children with ASD and TD over time. Twenty-four school-aged children (12 in each group), matched on expressive vocabulary, participated in an extended word learning paradigm. Performance on five measures of learning (referent identification, confrontation naming, defining, phonetic accuracy, and speech motor stability) were tracked across three sessions approximately one week apart to assess the influence of semantic richness on extended learning. Results indicate that children with ASD benefit from semantically rich learning contexts similarly to their peers with TD; however, one key difference between the two groups emerged - the children with ASD showed heightened shifts in speech motor stability. These findings offer insights into common learning mechanisms in children with ASD and TD, as well as pointing to a potentially distinct speech motor learning trajectory in children with ASD, providing a window into the emergence of stereotypic vocalizations in these children.
The ability to compare plays a key role in how humans learn, but words that describe relations between objects, like comparisons, are difficult to learn. We examined how children learn size comparison words, and how their interpretations of these change across development. One‐hundred‐and‐forty children in England (36–107 months; 68 girls; majority White) were asked to build block structures that were bigger , longer , smaller , shorter , or taller than an experimenter's. Children were most successful with words that refer to size increases. Younger children were less accurate with smaller and shorter , often building bigger structures. The dimensional aspect of taller emerged gradually. These findings suggest that children's interpretation of the meaning of size comparison words changes and becomes more precise across development.
Recent studies indicate that the opportunity to compare several stimuli associated with the same novel object noun, in contrast to a single stimulus design, promotes generalization along conceptually unifying dimensions. In two experiments (n= 240, 4-to-5-year-olds), we assessed the link between executive functions (EF) and vocabulary (EVIP; Dunn et al., 1993) on the one hand, and children’s novel word generalization performance in a comparison design on the other hand. The experiments used two types of materials: unfamiliar objects in Experiment 1 and familiar objects in Experiment 2. In both experiments, results revealed a significant association between generalization performance and flexibility while no significant links were observed with inhibition, working memory or vocabulary. For familiar objects, we anticipated that vocabulary would play a more significant role, which was not what was observed. We interpret these results in terms of children’s capacity to shift to other dimensions or to redescribe stimuli. Working memory (i.e., keeping track of dimensions), and inhibition (e.g., inhibiting irrelevant salient dimensions) did not reach significance. We also discuss the absence of correlation between vocabulary and the generalization task.
Previous work has found that shy children show chance‐level disambiguation and retention of novel word meanings in a typical lab‐based word learning task. This effect could be explained in terms of shy children's aversion to unfamiliarity disrupting the requisite attentional processes, because the task is marked by a high degree of unfamiliarity. To test this argument, we examined whether increasing the familiarity of the task facilitates shy children's ability to form and retain word meanings. Two‐year‐old children ( N = 23) took part in a word learning task in which their caregiver acted as the experimenter. On referent selection trials, children were presented with sets of three objects, one novel and two familiar, and were asked for either a familiar object using its known label, or a novel object using a novel word. Children were then tested on their retention of the previously formed novel word‐object mappings. In this context of increased familiarity, shyness was unrelated to performance on referent selection trials. However, shyness was positively related to children's retention of the word‐object mappings, meaning that shyer children outperformed less‐shy children on this measure of word learning. These findings show that context‐based familiarity interacts with intrinsic individual differences to affect word learning performance.
Cross-situational word learning (XSWL) – children’s ability to learn words by tracking co-occurrence statistics of words and their referents over time – has been identified as a fundamental mechanism underlying lexical learning. However, it is unknown whether children can acquire new words when faced with variable input in XSWL paradigms, such as varying object exemplars and variable speakers. In the present study, we examine the separate and combined effects of exemplar and speaker variability on XSWL in typically developing English-speaking monolingual children. Results revealed that variability in speakers and exemplars did not facilitate or hinder XSWL performance. However, input that varied in both speakers and exemplars simultaneously did hinder children’s word learning. Results from this work suggest that XSWL mechanisms may support categorization and generalization beyond word-object associations, but that accommodating multiple forms of variable input may incur costs. Overall, this research provides new theoretical insights into how fundamental mechanisms of word learning scale to more complex and naturalistic forms of input.
In studies of children's categorization, researchers have typically studied how encoding characteristics of exemplars contribute to children's generalization. However, it is unclear whether children's internal cognitive processes alone, independent of new information, may also influence their generalization. Thus, we examined the role that one cognitive process, forgetting, plays in shaping children's category representations by conducting three experiments. In the first two experiments, participants (NExp1=37, Mage=4.02 years; NExp2=32, Mage=4.48 years) saw a novel object labeled by the experimenter and then saw five new objects with between one and five features changed from the learned exemplar. The experimenter asked whether each object was a member of the same category as the exemplar; children saw the five new objects either immediately or after a five-minute delay. Children endorsed category membership at higher rates at immediate test than at delayed test, suggesting that children's category representations became narrower over time. In Experiment 3, we investigated forgetting as a key mechanism underlying the narrowing found in Experiments 1 and 2. We showed participants (NExp3=34, Mage=4.20 years) the same exemplars used in Experiments 1 and 2; then, either immediately or after a five-minute delay, we showed children seven individual object features and asked if each one had been part of the exemplar. Children's accuracy was lower after the delay, showing that they did indeed forget individual features. Taken together, these results show that forgetting plays an important role in changing children's newly-learned categories over time.
Children in everyday environments experience verbs separated by minutes or hours and linked to events that vary in their similarity. Prior studies have shown that seeing similar events can be beneficial for verb learning (e.g., complex events), but there is also evidence that varied events or seeing both similar and varied events is useful; more studies are needed. In addition, few prior verb studies have tested verb learning from spaced practice. In Study 1, 3½- and 4½-year-olds (N = 72) saw either three similar events, three varied events, or a single live event (control) while hearing a new verb; events were separated by 1-min delays. Results showed better performance in multiple-event conditions than in the single-event condition and showed more extensions with age. Specifically, children benefitted more from seeing varied events with age. In Study 2, 2½-, 3½-, and 4½-year-olds (N = 163) either saw similar and then varied events or saw all varied video events separated by 1-min delays or no delays. The youngest children performed significantly better in the similar first condition than in the all varied condition, showing the first evidence of this benefit following spaced practice. In addition, as in Study 1, performance after seeing varied events increased with age. Together, these studies show that children can compare events separated in time and that their ability to learn verbs from varied examples develops with age.
In order to learn the mappings from words to referents, children must integrate co‐occurrence information across individually ambiguous pairs of scenes and utterances, a challenge known as cross‐situational word learning. In machine learning, recent multimodal neural networks have been shown to learn meaningful visual‐linguistic mappings from cross‐situational data, as needed to solve problems such as image captioning and visual question answering. These networks are potentially appealing as cognitive models because they can learn from raw visual and linguistic stimuli, something previous cognitive models have not addressed. In this paper, we examine whether recent machine learning approaches can help explain various behavioral phenomena from the psychological literature on cross‐situational word learning. We consider two variants of a multimodal neural network architecture and look at seven different phenomena associated with cross‐situational word learning and word learning more generally. Our results show that these networks can learn word‐referent mappings from a single epoch of training, mimicking the amount of training commonly found in cross‐situational word learning experiments. Additionally, these networks capture some, but not all of the phenomena we studied, with all of the failures related to reasoning via mutual exclusivity. These results provide insight into the kinds of phenomena that arise naturally from relatively generic neural network learning algorithms, and which word learning phenomena require additional inductive biases.
There are two common challenges in particle swarm optimization (PSO) research, that is, selecting proper exemplars and designing an efficient learning model for a particle. In this article, we propose a triple archives PSO (TAPSO), in which particles in three archives are used to deal with the above two challenges. First, particles who have better fitness (i.e., elites) are recorded in one archive while other particles who offer faster progress, called profiteers in this article, are saved in another archive. Second, when breeding each dimension of a potential exemplar for a particle, we choose a pair of elite and profiteer from corresponding archives as two parents to generate the dimension value by ordinary genetic operators. Third, each particle carries out a specific learning model according to the fitness of its potential exemplars. Furthermore, there is no acceleration coefficient in TAPSO aiming to simplify the learning models. Finally, if an exemplar has excellent performance, it will be regarded as an outstanding exemplar and saved in the third archive, which can be reused by inferior particles aiming to enhance the exploitation and to save computing resources. The experimental results and comparisons between TAPSO and other eight PSOs on 30 benchmark functions and four real applications suggest that TAPSO attains very promising performance in different types of functions, contributing to both higher solution accuracy and faster convergence speed. Furthermore, the effectiveness and efficiency of these new proposed strategies are discussed based on extensive experiments.
Learning words from ambiguous naming events is difficult. In such situations, children struggle with not attending to task irrelevant information when learning object names. The current study reduces the problem space of learning names for object categories by holding color constant between the target and other extraneous objects. We examine how this influences two types of word learning (retention and generalization) in both 30-month-old children (Experiment 1) and the iCub humanoid robot (Experiment 2). Overall, all children and iCub performed well on the retention trials, but they were only able to generalize the novel names to new exemplars of the target categories if the objects were originally encountered in sets with objects of the same colors, not if the objects were originally encountered in sets with objects of different colors. These data demonstrate that less information presented during the learning phase narrows the problem space and leads to better word learning success for both children and iCub. Findings are discussed in terms of cognitive load and desirable difficulties.
How do children learn to link word to world? This question continues to be the subject of vibrant debate and research. Key insights into the processes of lexical development have steadily grown, beginning with the work of Roger Brown. This chapter highlights infants’ abilities to carve the sound stream into linguistic units and the event stream into non-linguistic units, so that word-referent mappings can be learned. High quality input, both linguistic (e.g., contingent conversations between parent and child) and non-linguistic (e.g., joint attention toward objects and events), is essential for the development of these foundational abilities and for word learning. We also discuss current theories tackling the so-called “mapping problem.” These proposals are beginning to converge on the idea that the processes children use to discover word meanings are complex, involving the use of associative, social, and linguistic cues, and change over time.
A nap soon after encoding leads to better learning in infancy. However, whether napping plays the same role in preschoolers' learning is unclear. In Experiment 1 (N = 39), 3-year-old habitual and nonhabitual nappers learned novel verbs before a nap or a period of wakefulness and received a generalization test examining word extension to novel actors after 24 hr. Only habitual and nonhabitual nappers who napped after learning generalized 24 hr later. In Experiment 2 (N = 40), children learned the same verbs but were tested within 2–3 min of training. Here, habitual and nonhabitual nappers retained the mappings but did not generalize. The results suggest that naps consolidate weak learning that habitual and nonhabitual nappers would otherwise forget over periods of wakefulness.
In 3 experiments, the authors used an object-examining task to investigate the role of perceptual similarity in infants’ categorization. In Experiment 1, infants were familiarized with a set of either perceptually similar or perceptually variable exemplars from 1 category and tested with novel exemplars from both categories. Ten-month-olds did not respond to the category in either condition, and 13-month-olds responded categorically in both conditions but somewhat differently in the 2 conditions. Experiment 2 showed that when 10-month-olds were familiarized with similar exemplars but not with variable exemplars, they responded to the categorical distinction when given tests with typical exemplars. Experiment 3 established that 10-month-olds could differentiate among the exemplars. These results suggest that the perceptual similarity of the exemplars influences infants’ recognition of categorical distinctions.
Comparison mechanisms have been implicated in the development of abstract, relational thought, including object categorization. D. Gentner and L. L. Namy (1999) found that comparing 2 perceptually similar category members yielded taxonomic categorization, whereas viewing a single member of the target category elicited shallower perceptual responding. The present experiments tested 2 predictions that follow from Gentner and Namy's (1999) model: (a) Comparison facilitates categorization only when the targets to be compared share relational commonalities, and (b) providing common labels for targets invites comparison, whereas providing conflicting labels deters it. Four-year-olds participated in a forced-choice task. They viewed 2 perceptually similar target objects and were asked to "find another one." Results suggest an important role for comparison in lexical and conceptual development.
A large literature has documented that comparison and contrast lead to better performance in a variety of tasks. However, studies of comparison and contrast present contradictory conclusions as to when and how these processes benefit learners. Across four studies, we examined how the specifics of the comparison and contrast task affect performance by systematically manipulating the feature variation and category structure in a category extension task performed by 3-year-old and 4-year-old children. Studies 1 (n = 48, M = 42.6 months) and 2 (n = 48, M = 42. 4 months) investigated comparison and contrast with high-density categories. Studies 3A (n = 60, M = 43.47 months), 3B (n = 48, M = 53. 2 months) and 4 (n = 48, M = 53.7 months) investigated comparison and contrast with low-density categories. Results indicated both category structure and feature variation affect the efficacy of comparison and contrast. Copyright © 2012 John Wiley & Sons, Ltd.
This paper investigates whether preverbal children form categories at different levels of abstraction in any specific sequence. In a longitudinal study, 20 infants were each tested twice, at 8 and 12 months of age. Half of the children solved a global-level task (animals-furniture), followed by a basic-level task (either dogs-birds, or chairs-tables) during each session. The other half received the basic-level task only. During familiarisation, all infants freely explored a series of four different exemplars from the same category presented one at a time. Infants saw all objects twice, for a total of eight trials. During the test phase, a new exemplar from the familiar category was presented, followed by a different-category exemplar. At 8 months of age, children discriminated between categories in the global-level task, but failed to do so in the basic-level task. At 12 months of age, infants recognised a category change in the basic-level task, but treated both test items as equally new in the global-level task. These findings support the hypothesis that infants younger than 1 year of age show a global-to-basic-level shift in category formation.
Young children learn words from a variety of situations, including shared storybook reading. A recent study by Horst et al. (2011a) demonstrates that children learned more new words during shared storybook reading if they were read the same stories repeatedly than if they were read different stories that had the same number of target words. The current paper reviews this study and further examines the effect of contextual repetition on children's word learning in both shared storybook reading and other situations, including fast mapping by mutual exclusivity. The studies reviewed here suggest that the same cognitive mechanisms support word learning in a variety of situations. Both practical considerations for experimental design and directions for future research are discussed.
Classic approaches to word learning emphasize referential ambiguity: In naming situations, a novel word could refer to many possible objects, properties, actions, and so forth. To solve this, researchers have posited constraints, and inference strategies, but assume that determining the referent of a novel word is isomorphic to learning. We present an alternative in which referent selection is an online process and independent of long-term learning. We illustrate this theoretical approach with a dynamic associative model in which referent selection emerges from real-time competition between referents and learning is associative (Hebbian). This model accounts for a range of findings including the differences in expressive and receptive vocabulary, cross-situational learning under high degrees of ambiguity, accelerating (vocabulary explosion) and decelerating (power law) learning, fast mapping by mutual exclusivity (and differences in bilinguals), improvements in familiar word recognition with development, and correlations between speed of processing and learning. Together it suggests that (a) association learning buttressed by dynamic competition can account for much of the literature; (b) familiar word recognition is subserved by the same processes that identify the referents of novel words (fast mapping); (c) online competition may allow the children to leverage information available in the task to augment performance despite slow learning; (d) in complex systems, associative learning is highly multifaceted; and (e) learning and referent selection, though logically distinct, can be subtly related. It suggests more sophisticated ways of describing the interaction between situation- and developmental-time processes and points to the need for considering such interactions as a primary determinant of development. (PsycINFO Database Record (c) 2012 APA, all rights reserved).
Conducted 9 experiments with a total of 663 undergraduates using the technique of priming to study the nature of the cognitive representation generated by superordinate semantic category names. In Exp I, norms for the internal structure of 10 categories were collected. In Exps II, III, and IV, internal structure was found to affect the perceptual encoding of physically identical pairs of stimuli, facilitating responses to physically identical good members and hindering responses to identical poor members of a category. Exps V and VI showed that the category name did not generate a physical code (e.g., lines or angles), but rather affected perception of the stimuli at the level of meaning. Exps VII and VIII showed that while the representation of the category name which affected perception contained a depth meaning common to words and pictures which enabled Ss to prepare for either stimulus form within 700 msec, selective reduction of the interval between prime and stimulus below 700 msec revealed differentiation of the coding of meaning in preparation for actual perception. Exp IX suggested that good examples of semantic categories are not physiologically determined, as the effects of the internal structure of semantic categories on priming (unlike the effects for color categories) could be eliminated by long practice. (57 ref) (PsycINFO Database Record (c) 2012 APA, all rights reserved)
In 2 experiments, adults and children were tested in an object-selection task that examined whether Ss would (1) map a novel word onto a previously unnamed object and (2) extend the newly learned word to another exemplar. Exp 3 was a control study. Ss overwhelmingly selected the novel object as the referent for the novel term, even though the new label was never explicitly linked to the novel object. Ss also extended the new term and allowed it to preempt yet another novel label from applying to the just-named object. The existence of several lexical principles and the power of indirect word learning is supported. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
The acquisition of word meaning is often partially attributed to fast mapping. However, recent research suggests that fast mapping and word learning may represent distinct components of language acquisition. Here we examine their interaction with a Hebbian Normalized Recurrence Network, a connectionist architecture that captures both online processing and long-term statistical learning. After training on a small lexicon, the model performed well above chance on a fast mapping task. Careful analyses of the weight changes, however, suggest that the fast mapping task can be solved with minimal learning. Thus, this model not only captures both long-term learning and online processes, but also provides unique insights regarding the relationship between fast mapping and word learning and that the two should be carefully distinguished.
The current study examines how focusing children’s attention immediately after fast mapping improves their ability to retain novel names. Previous research suggests that young children can only retain novel names presented via referent selection if ostensive naming is provided and that such explicit naming works by increasing children’s attention to the target and decreasing their attention to the competitor objects (Horst and Samuelson, 2008). This explanation of the function of ostensive naming after referent selection trials was tested by drawing 24-month-old children’s attention to the target either by illuminating the target, covering the competitors, or both. A control group was given a social pragmatic cue (pointing). Children given social pragmatic cue support did not demonstrate retention. However, children demonstrated retention if the target object was illuminated, and also when it was illuminated and the competitors simultaneously dampened. This suggests that drawing children’s attention to the target object in a manner that helps focus children’s attention is critical for word learning via referent selection. Directing attention away from competitors while also directing attention toward a target also aids in the retention of novel words.
Upon fast mapping, children rarely retain new words even over intervals as short as 5 min. In this study, we asked whether the memory process of encoding or consolidation is the bottleneck to retention. Forty-nine children, mean age 33 months, were exposed to eight 2- or-3-syllable nonce neighbors of words in their existing lexicons. Didactic training consisted of six exposures to each word in the context of its referent, an unfamiliar toy. Productions were elicited four times: immediately following the examiner’s model, and at 1-min-, 5-min-, and multiday retention intervals. At the final two intervals, the examiner said the first syllable and provided a beat gesture highlighting target word length in syllables as a cue following any erred production. The children were highly accurate at immediate posttest. Accuracy fell sharply over the 1-min retention interval and again after an additional 5 min. Performance then stabilized such that the 5-min and multiday posttests yielded comparable performance. Given this time course, we conclude that it was not the post-encoding process of consolidation but the process of encoding itself that presented the primary bottleneck to retention. Patterns of errors and responses to cueing upon error suggested that word forms were particularly vulnerable to partial decay during the time course of encoding.
Research suggests that variability of exemplars supports successful object categorization; however, the scope of variability's support at the level of higher-order generalization remains unexplored. Using a longitudinal study, we examined the role of exemplar variability in first- and second-order generalization in the context of nominal-category learning at an early age. Sixteen 18-month-old children were taught 12 categories. Half of the children were taught with sets of highly similar exemplars; the other half were taught with sets of dissimilar, variable exemplars. Participants' learning and generalization of trained labels and their development of more general word-learning biases were tested. All children were found to have learned labels for trained exemplars, but children trained with variable exemplars generalized to novel exemplars of these categories, developed a discriminating word-learning bias generalizing labels of novel solid objects by shape and labels of nonsolid objects by material, and accelerated in vocabulary acquisition. These findings demonstrate that object variability leads to better abstraction of individual and global category organization, which increases learning outside the laboratory.
Purpose
To investigate whether phonological or semantic encoding cues improved the fast mapping or word learning performance of preschoolers with specific language impairment (SLI) or typical development (TD) and whether performance varied for words containing high- or low-frequency sublexical sequences that named familiar or unfamiliar objects.
Method
Forty-two preschoolers with SLI, 42 preschoolers with TD matched for age and gender to the children with SLI, and 41 preschoolers with TD matched for expressive vocabulary and gender to the children with SLI learned words in a supported learning context. Fast mapping, word learning, and post-task performance were assessed.
Results
Encoding cues had no effect on fast mapping performance for any group or on the number of words children learned to comprehend. Encoding cues appeared to be detrimental to word production for children with TD. Across groups, a clear learning advantage was observed for words with low-frequency sequences and, to a lesser extent, words associated with an unfamiliar object.
Conclusion
The results suggest that phonotactic probability and previous lexical knowledge affect word learning in similar ways for children with TD and SLI and that encoding cues were not beneficial for any group.
This study experimentally tested the relationship between children's lexicon size and their ability to learn new words within the domain of color. We manipulated the size of 25 20-month-olds' color lexicons by training them with two, four, or six different color words over the course of eight training sessions. We subsequently tested children's ability to extend new color words to new instances. We found that training with a broader number of color words led to increased extension of new words. The results suggest that children's learning history predicts their ability to learn new words within domains.
Two experiments explored the ability of 18-month-old infants to form an abstract categorical representation of tight-fit spatial relations in a visual habituation task. In Experiment 1, infants formed an abstract spatial category when hearing a familiar word (tight) during habituation but not when viewing the events in silence or when hearing a novel word. In Experiment 2, infants were given experience viewing and producing tight-fit relations while an experimenter labeled them with a novel word. Following this experience, infants formed the tight-fit spatial category in the visual habituation task, particularly when hearing the novel word again during habituation. Results suggest that even brief experience with a label and tight-fit relations can aid infants in forming an abstract categorical representation of tight-fit relations.
The spacing effect describes the robust phenomenon whereby memory is enhanced when learning events are distributed, instead of being presented in succession. We investigated the effect of spacing on children's memory and category induction. Three-year-old children were presented with two tasks, a memory task and a category induction task. In the memory task, identical instances of an object were presented and then tested in a multiple choice test. In the category induction task, different instances of a category were presented and tested in a multiple choice test. In both tasks, presenting the instances in a spaced sequence resulted in more learning than presenting the instances in a massed sequence, despite the difficulty created by the spaced sequence. The spaced sequence increased the difficulty of the task by allowing children time to forget the previous instance during the spaced interval.
Concepts embody our knowledge of the kinds of things there are in the world. Tying our past experiences to our present interactions with the environment, they enable us to recognize and understand new objects and events. Concepts are also relevant to understanding domains such as social situations, personality types, and even artistic styles. Yet like other phenomenologically simple cognitive processes such as walking or understanding speech, concept formation and use are maddeningly complex.
Research since the 1970s and the decline of the "classical view" of concepts have greatly illuminated the psychology of concepts. But persistent theoretical disputes have sometimes obscured this progress. The Big Book of Concepts goes beyond those disputes to reveal the advances that have been made, focusing on the major empirical discoveries. By reviewing and evaluating research on diverse topics such as category learning, word meaning, conceptual development in infants and children, and the basic level of categorization, the book develops a much broader range of criteria than is usual for evaluating theories of concepts.
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Infants across the world’s communities are raised in vastly different environments, surrounded by different objects, different customs, and different languages. Yet despite these differences, there are striking similarities in the most fundamental aspects of infant cognitive and language development. Within their first two years, infants develop two uniquely human capacities: they naturally establish rich and flexible repertoires of object categories, and they spontaneously acquire their native language. Each of these capacities, considered on its own, is a remarkable feat. But perhaps even more remarkable is the fact that even before they begin to produce words on their own, infants’ conceptual and linguistic advances are powerfully and implicitly linked. These early links foster the acquisition of a stable set of object categories, guide the acquisition of the early lexicon, and serve as a foundation for the evolution of the finely tuned links between language and conceptual organization that characterize the mature system.
In two experiments we examined the relation between productive vocabulary and categorization at the basic and superordinate levels. Experiment 1 assessed categorization using a spontaneous object-manipulation task; Experiment 2 used a structured task employing 3 different levels of verbal support. In both experiments 24-month-old children participated in two sessions, with different levels of categorization tested at each session. Each child's productive vocabulary was assessed using either the Reznick & Goldsmith (1989) short parental report or the MacArthur Communicative Development Inventory. In both experiments, children performed equally well at the basic and superordinate levels, regardless of the task or level of verbal support. In Experiment 1 productive vocabulary was correlated with categorization at the basic level: children with larger productive vocabularies were more successful on basic-level tasks. The same relation between productive vocabulary and basic-level categorization was seen in the lowest verbal support condition of Experiment 2. There was no relation between vocabulary score and categorization at the superordinate level in either experiment. Possible implications of these findings are discussed.
Although vocabulary acquisition requires children learn names for multiple things, many investigations of word learning mechanisms teach children the name for only one of the objects presented. This is problematic because it is unclear whether children's performance reflects recall of the correct name-object association or simply selection of the only object that was singled out by being the only object named. Children introduced to one novel name may perform at ceiling as they are not required to discriminate on the basis of the name per se, and appear to rapidly learn words following minimal exposure to a single word. We introduced children to four novel objects. For half the children, only one of the objects was named and for the other children, all four objects were named. Only children introduced to one word reliably selected the target object at test. This demonstration highlights the over-simplicity of one-word learning paradigms and the need for a shift in word learning paradigms where more than one word is taught to ensure children disambiguate objects on the basis of their names rather than their degree of salience.
Does making an inference lead to better learning than being instructed directly? Two experiments evaluated preschoolers' ability to learn new words, comparing their memory for words learned via inference or instruction. On Inference trials, one familiar and one novel object was presented and children were asked to Point at the [object name (i.e., pizer)]. These trials required the child to infer that the novel label referred to the novel object and not to the familiar object. On Instruction trials, a novel object label directly referred to a novel object (e.g., This is a glark) and no familiar distracter object was shown. We found that although children looked longer at the novel target on Instruction trials, they showed poorer retention of the newly learned label compared to words learned on Inference trials. Hence, we found that inferential learning was superior to instruction. Relevance for optimal learning contexts and education are discussed.
Recent research demonstrates that both real-time variability in perceptual input and task demands influence young children’s word learning and categorisation. The current study extends these findings by testing both children and a dynamic field theory (DFT) computational model in a category labelling task. Specifically, children and the model were introduced to multiple category members that were either moderately or highly variable. Both children and the model were better able to learn category labels when the individual category members were moderately variable. Overall, these findings have implications for both our understanding of children’s categorization and the use of computational models to investigate cognition more generally.
Children learn words with remarkable speed and flexibility. However, the cognitive basis of young children’s word learning is disputed. Further, although research demonstrates that children’s categories and category labels are interdependent, how children learn category labels is also a matter of debate. Recently, biologically plausible, computational simulations of children’s behavior in experimental tasks have investigated the cognitive processes that underlie learning. The ecological validity of such models has been successfully tested by deploying them in robotic systems (Morse, Belpaeme, Cangelosi, & Smith, 2010). The authors present a simulation of children’s behavior in a word learning task (Twomey & Horst, 2011) via an embodied system (iCub; Metta, et al., 2010), which points to associative learning and dynamic systems accounts of children’s categorization. Finally, the authors discuss the benefits of integrating computational and robotic approaches with developmental science for a deeper understanding of cognition.
How do children learn that the word "dog" refers not to all four-legged animals, and not just to Ralph, but to all members of a particular species? How do they learn the meanings of verbs like "think," adjectives like "good," and words for abstract entities such as "mortgage" and "story"? The acquisition of word meaning is one of the fundamental issues in the study of mind.
According to Paul Bloom, children learn words through sophisticated cognitive abilities that exist for other purposes. These include the ability to infer others' intentions, the ability to acquire concepts, an appreciation of syntactic structure, and certain general learning and memory abilities. Although other researchers have associated word learning with some of these capacities, Bloom is the first to show how a complete explanation requires all of them. The acquisition of even simple nouns requires rich conceptual, social, and linguistic capacities interacting in complex ways.
This book requires no background in psychology or linguistics and is written in a clear, engaging style. Topics include the effects of language on spatial reasoning, the origin of essentialist beliefs, and the young child's understanding of representational art. The book should appeal to general readers interested in language and cognition as well as to researchers in the field.
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During the second year of life, infants develop a preference to attach novel labels to novel objects. This behavior is commonly known as “mutual exclusivity” (Markman, 198914.
Markman , E. M. 1989 . Categorization and naming in children: Problems of induction. , Cambridge, MA : MIT Press . View all references). In an intermodal preferential looking experiment with 19.5- and 22.5-month-olds, stimulus repetition was critical for observing mutual exclusivity. On the first occasion that a novel label was presented with 1 familiar object and 1 novel object, looking behavior was unsystematic. However, on reexposure to the same stimuli, 22.5-month-olds looked preferentially at the novel object prior to the re-presentation of the novel label. These findings suggest a powerful memory mechanism for novel labels and objects, enabling mutual exclusivity to emerge across repeated exposures to potential referents.
A series of 3 experiments are reviewed in which infants between 4 and 10 months of age were familiarized with members of 2 basic-level object categories. The degree of distinctiveness between categories was varied. Preference tests were intended to determine whether infants formed a single category representation (at a more global level) or 2 basic-level representations. Across 3 experiments, 10-month-old infants appeared to have formed multiple basic-level categories, whereas younger infants tended to form broader, more inclusive representations. The tendency to form multiple categories was influenced to some extent by category distinctiveness. Whereas 10-month-olds formed separate categories for all contrasts, 7-month-olds did so only when the 2 familiarized categories were from separate global domains. A perceptual account of the global-to-basic shift in early categorization is offered. Task dependencies in early categorization are also discussed.
Four experiments explored the processes that bridge between referent selection and word learning. Twenty-four-month-old infants were presented with several novel names during a referent selection task that included both familiar and novel objects and tested for retention after a 5-min delay. The 5-min delay ensured that word learning was based on retrieval from long-term memory. Moreover, the relative familiarity of objects used during the retention test was explicitly controlled. Across experiments, infants were excellent at referent selection, but very poor at retention. Although the highly controlled retention test was clearly challenging, infants were able to demonstrate retention of the first 4 novel names presented in the session when referent selection was augmented with ostensive naming. These results suggest that fast mapping is robust for reference selection but might be more transient than previously reported for lexical retention. The relations between reference selection and retention are discussed in terms of competitive processes on 2 timescales: competition among objects on individual referent selection trials and competition among multiple novel name–object mappings made across an experimental session.
2 studies investigate whether 18-month-old children spontaneously sort objects into basic-level categories, and how this ability is related to naming. In Study 1, 18-month-old children were given spontaneous sorting tasks, involving both identical objects and objects with basic-level intracategory variation. Children were scored as having passed the tasks if they produced “exhaustive grouping,” that is, physically grouped all the objects of one kind into one location and the objects of the other kind into a different location. The children also received means-ends and object-permanence tasks. Children's parents received a checklist of early names. Children who produced exhaustive grouping used significantly more names than those who did not, in both identical and basic-level cases. There was no such relation between object-permanence and naming or between means-ends performance and naming. In Study 2, children received arrays of the same objects, with either identical objects or objects with basic-level variation in each group. No significant differences were found between the identical and basic-level tasks. However, as in the previous task, performance on both types of categorization was related to naming. Children who produced exhaustive grouping were reported to produce more names than those who did not. There appears to be a close relation between object categorization and naming in young children. The theoretical implications of this empirical association are discussed.
Toddlers' acquisition of the Novel Name–Nameless Category (N3C) principle was examined to investigate the developmental lexical principles framework and the applicability of the specificity hypothesis to relations involving lexical principles. In Study 1, we assessed the ability of 32 children between the ages of 16 and 20 months to use the N3C principle (operationally defined as the ability to fast map). As predicted, only some of the children could fast map. This finding provided evidence for a crucial tenet of the developmental lexical principles framewor: Some lexical principles are not available at the start of language acquisition. Children who had acquired the N3C principle also had significantly larger vocabularies and were significantly more likely to demonstrate 2-category exhaustive sorting abilities than children who had not acquired the principle. The 2 groups of children did not differ in either age or object permanence abilities. The 16 children who could not fast map were followed longitudinally until they attained a vocabulary spurt; at that time, their ability to fast map was retested (Study 2). Results provided a longitudinal replication of the findings of Study 1. Implications of these findings for both the developmental lexical principles framework and the specificity hypothesis are discussed.
Recent research demonstrated that although twenty-four month-old infants do well on the initial pairing of a novel word and novel object in fast-mapping tasks, they are unable to retain the mapping after a five-minute delay. The current study examines the role of familiarity with the objects and words on infants' ability to bridge between the initial fast mapping of a name and object, and later retention in the service of slow mapping. Twenty-four-month-old infants were familiarized with either novel objects or novel names prior to the referent selection portion of a fast-mapping task. When familiarized with the novel objects, infants retained the novel mapping after a delay, but not when familiarized with the novel words. This suggests familiarity with the object versus the word form leads to differential encoding of the name-object link. We discuss the implications of this finding for subsequent slow mapping.
Three experiments directly compared infants' categorization in variations of the visual familiarization task. In each experiment, 4- or 6-month-old infants were familiarized with a collection of dogs or cats and then their response to novel dogs and cats was assessed. In Experiment 1, 4-month-old infants responded to the exclusive distinction of dogs or cats when tested in a paired-comparison task. In Experiments 2 and 3, 6-month-old infants, but not 4-month-old infants, responded to this same distinction in a successive presentation task, even when the amount of familiarization was equated to that of the paired comparison task. Therefore, familiarization with a particular set of stimuli does not induce infants to respond to a single category but rather they respond to different categories depending on features of the task.
Two experiments were conducted to investigate the representation of categories of kitchen and bathroom things in 14- and 20-month-old children. These contextual categories are based on spatiotemporal relatedness rather than on the similarity of form or function that underlies the more frequently studied taxonomic categories. In the first experiment, a preferential-looking technique was used that demonstrated sensitivity to a kitchen category but not to a bathroom category. In the second experiment, an object-manipulation task was used that demonstrated sensitivity to both categories. The object-manipulation task was also used to show the presence of a basic-level category of cars and a more global category of animals. The data indicate that a variety of categories are represented at an early age.
Recent research on children's word learning has led to a paradox. Although word learning appears to be a deep source of insight into conceptual knowledge for children, preschoolers often categorize objects on the basis of shallow perceptual features such as shape. The current studies seek to resolve this discrepancy. We suggest that comparing multiple instances of a category enables children to extract deeper relational commonalities among category members. We examine 4-year-olds' categorization behaviors when asked to select a match for a target object (e.g., an apple) between a perceptually similar, out-of-kind object (e.g., a balloon) and a perceptually different category match (e.g., a banana). Children who learn a novel word as a label for multiple instances of the category are more likely to select the category match over the perceptual match. Children who learn a label for only one instance are equally likely to select either alternative. This effect is present even when individual target instances are more perceptually similar to the perceptual choice than to the category choice. We conclude that structural alignment processes may be important in the development of category understanding.
What mechanism implements the mutual exclusivity bias to map novel labels to objects without names? Prominent theoretical accounts of mutual exclusivity (e.g., Markman, 1989, 1990) propose that infants are guided by their knowledge of object names. However, the mutual exclusivity constraint could be implemented via monitoring of object novelty (see Merriman, Marazita, & Jarvis, 1995). We sought to discriminate between these contrasting explanations across two preferential looking experiments with 22-month-olds. In Experiment 1, infants viewed three objects: one name-known, two name-unknown. Of the two name-unknown objects, one was novel, and the other had been previously familiarized. The infants responded to hearing a novel label by increasing attention only to the novel, name-unknown object. In a second experiment in which the name-known object was absent, a novel label increased infants' attention to a novel object beyond baseline preference for novelty. The experiments provide clear evidence for a novelty-based mechanism. However, differences in the time course of disambiguation across experiments suggest that novelty processing may be influenced by contextual factors.
Determining the referent of a novel name is a critical task for young language learners. The majority of studies on children's referent selection focus on manipulating the sources of information (linguistic, contextual and pragmatic) that children can use to solve the referent mapping problem. Here, we take a step back and explore how children's endogenous biases towards novelty and their own familiarity with novel objects influence their performance in such a task. We familiarized 2-year-old children with previously novel objects. Then, on novel name referent selection trials children were asked to select the referent from three novel objects: two previously seen and one completely novel object. Children demonstrated a clear bias to select the most novel object. A second experiment controls for pragmatic responding and replicates this finding. We conclude, therefore, that children's referent selection is biased by previous exposure and children's endogenous bias to novelty.
Previous research suggests that competition among the objects present during referent selection influences young children's ability to learn words in fast mapping tasks. The present study systematically explored this issue with 30-month-old children. Children first received referent selection trials with a target object and either two, three or four competitor objects. Then, after a short delay, children were tested on their ability to retain the newly fast-mapped names. Overall, the number of competitors did not affect children's ability to form the initial name-object mappings. However, only children who encountered few competitors during referent selection demonstrated significant levels of retention. Results and implications are discussed in terms of the role of competition in studies of children's fast mapping. The relationship between referent selection and full word learning is also discussed.
Infants do not readily organize using form similarity: 6- to 7-month-olds familiarized with horizontal or vertical bars (filled rectangles) do not display a subsequent preference for a novel column versus row organization of X-O elements (Quinn and Bhatt, 2006 Journal of Experimental Psychology: Human Perception and Performance 32 1221-1230). In experiment 1, infants were familiarized with more complex bars composed of beads or crosshatches, and performance was again unsuccessful. In experiment 2, all three bar types were presented during familiarization and infants performed successfully, indicating that variability in pattern information depicting an invariant structure enhances the learning of perceptual organization. In experiment 3, we examined whether the manner in which variability is experienced (simultaneous versus sequential contrast) impacts this learning. One group of infants was familiarized with a single pattern containing the three different bar types (within-trial variability), and another was presented with the same three bar types, but with each appearing on a different trial (across-trial variability). Only the across-trial variability group performed successfully, suggesting that trial-to-trial change in local element information induced by sequential presentation is a significant factor in facilitating the learning of perceptual organization.
We examined the role of the comparison process and shared names on preschoolers' categorization of novel objects. In our studies, 4-year-olds were presented with novel object sets consisting of either one or two standards and two test objects: a shape match and a texture match. When children were presented with one standard, they extended the category based on shape regardless of whether the objects were named. When children were presented with two standards that shared the same texture and the objects were named with the same noun, they extended the category based on texture. The opportunity to compare two standards, in the absence of shared names, led to an attenuation of the effect of shape. These findings demonstrate that comparison plays a critical role in the categorization of novel objects and that shared names enhance this process.
The present research studied 3- and 4-month-old infants' ability to acquire two categories simultaneously. A familiarization-novelty preference procedure and geometrical form categories were used in all experiments. In Experiments I and 3, infants were familiarized with either a single form category, two form categories, or a single form category plus a set of forms that did not define a category. The results showed that, despite increased attentional and memorial demands, presentation of an additional form category did not harm the efficiency of categorization (Experiment 1) and changed the representation of the form category information from exemplars to a prototype (Experiment 3). Contrasting form information that was not categorical in structure decreased the infant's ability to recognize new members of the single familiar category (Experiment 1) and hindered the infant's ability to form a categorical representation (Experiment 3). The categorization behavior observed in Experiment 1, as indexed by the generalization of habituation to novel forms from a familiar category, was shown not to be a consequence of the inability to discriminate between individual members from the familiar form category (Experiment 2). The implications of these results for cognitive development are discussed.
Infants' sensitivity to correlations or co-occurrences among attributes may play a role in abilities ranging from pattern or object recognition to category formation. The present set of experiments investigated 4-, 7-, and 10-month-old infants' ability to perceive and base novelty responses on correlations among perceptual attributes in a category-like context (i.e., with the correlation embedded in a set of discriminable stimuli). In a habituation-dishabituation paradigm, 10-month-old infants clearly responded on the basis of the correlation among attributes. In contrast, 4- and 7-month-old infants responded primarily on the basis of specific featural information, but did not respond reliably to the correlation. It is suggested that the sensitivity to correlated attributes demonstrated by 10-month-old infants may have implications for the processes underlying the infants' categorization abilities.
Toddlers' acquisition of the Novel Name-Nameless Category (N3C) principle was examined to investigate the developmental lexical principles framework and the applicability of the specificity hypothesis to relations involving lexical principles. In Study 1, we assessed the ability of 32 children between the ages of 16 and 20 months to use the N3C principle (operationally defined as the ability to fast map). As predicted, only some of the children could fast map. This finding provided evidence for a crucial tenet of the developmental lexical principles framework: Some lexical principles are not available at the start of language acquisition. Children who had acquired the N3C principle also had significantly larger vocabularies and were significantly more likely to demonstrate 2-category exhaustive sorting abilities than children who had not acquired the principle. The 2 groups of children did not differ in either age or object permanence abilities. The 16 children who could not fast map were followed longitudinally until they attained a vocabulary spurt; at that time, their ability to fast map was retested (Study 2). Results provided a longitudinal replication of the findings of Study 1. Implications of these findings for both the developmental lexical principles framework and the specificity hypothesis are discussed.
The paired-preference procedure was used in a series of experiments to explore the abilities of infants aged 3 and 4 months to categorize photographic exemplars from natural (adult-defined) basic-level categories. The question of whether the categorical representations that were evidenced excluded members of a related, perceptually similar category was also investigated. Experiments 1-3 revealed that infants could form categorical representations for dogs and cats that excluded birds. Experiment 4 showed that the representation for cats also excluded dogs, but that the representation for dogs did not exclude cats. However, a supplementary experiment showed that the representation for dogs did exclude cats when the variability of the dog exemplars was reduced to match that of the cat exemplars. The results are discussed in terms of abilities necessary for the formation of more complex categorical representations.
Recent research has documented specific linkages between language and conceptual organization in the developing child. However, most of the evidence for these linkages derives from children who have made significant linguistic and conceptual advances. We therefore focus on the emergence of one particular linkage--the noun-category linkage--in infants at the early stages of lexical acquisition. We propose that when infants embark upon the process of lexical acquisition, they are initially biased to interpret a word applied to an object as referring to that object and to other members of its kind. We further propose that this initial expectation will become increasingly specific over development, as infants begin to distinguish among the grammatical categories as they are marked in their native language and assign them more specific types of meaning. To test this hypothesis, we conducted three experiments using a modified novelty-preference paradigm to reveal whether and how novel words influence object categorization in 12- to 13-month old infants. The data reveal that a linkage between words and object categories emerges early enough to serve as a guide in infants' efforts to map words to meanings. Both nouns and adjectives focused infants' attention on object categories, particularly at the superordinate level. Further, infants' progress in early word learning was associated with their appreciation of this linkage between words and object categories. These results are interpreted within a developmental and cross-linguistic account of the emergence of linkages between linguistic and conceptual organization.
In 3 experiments, the authors used an object-examining task to investigate the role of perceptual similarity in infants' categorization. In Experiment 1, infants were familiarized with a set of either perceptually similar or perceptually variable exemplars from 1 category and tested with novel exemplars from both categories. Ten-month-olds did not respond to the category in either condition, and 13-month-olds responded categorically in both conditions but somewhat differently in the 2 conditions. Experiment 2 showed that when 10-month-olds were familiarized with similar exemplars but not with variable exemplars, they responded to the categorical distinction when given tests with typical exemplars. Experiment 3 established that 10-month-olds could differentiate among the exemplars. These results suggest that the perceptual similarity of the exemplars influences infants' recognition of categorical distinctions.
This paper examines children's early noun vocabularies and their interpretations of names for solid and non-solid things. Previous research in this area assumes that ontology, category organization and syntax correspond in the nouns children learn early such that categories of solid things are organized by shape similarity and named with count nouns and categories of non-solid things are organized by material similarity and named with mass nouns. In Experiment 1 we examine the validity of this assumption in a corpus of early-learned nouns and conclude that one side of the solidity-syntax-category organization mapping is favored. In our second experiment we examine the relation between early noun vocabulary development and novel word generalization. We find that children between 17 and 33 months of age do not systematically generalize names for solid things by shape similarity until they already know many nouns, and do not systematically generalize names for non-solid substances by material similarity. The implications for children's acquisition of the ontological distinction, count/mass syntax, and novel nouns are discussed.
A controversial question is whether language acquisition is the result of domain-general or domain-specific principles. Focusing on word-learning, Markson and Bloom (Nature 385(6619) (1997) 813) recently argued that the ability to learn and retain new words (count nouns) is the result of abilities that are not specific to language. In the current experiment, we replicate their empirical finding, but challenge their domain-general interpretation by highlighting a crucial distinction between the principles involved in learning a count noun, as compared to learning a fact. The current results confirm that learning count nouns and facts involve (at least) two common components: establishing a mapping to a designated individual, and retaining this mapping over time. However, these results go further to document that the processes invoked in the acquisition of words differ from those invoked in the acquisition of facts. Children spontaneously and systematically extended a novel count noun exclusively to other members of the same category, but revealed no such systematicity when extending a fact. This illustrates that there are principles that are invoked in learning a novel count noun that are not invoked in learning a fact.